Python build warnings

[tbirdso]

In https://github.com/KitwareMedical/ITKStrain/actions/runs/3290689611/jobs/5423865575:

[11/20] Run igenerator.py for Strain
itkStrainImageFilter: warning(4): ITK type not wrapped, or currently not known: itk::ImageToImageFilter< itk::Image< itk::Vector< double, 2 >, 2 >, itk::Image< itk::CovariantVector< double, 2 >, 2 > >
itkStrainImageFilter: warning(4): ITK type not wrapped, or currently not known: itk::ImageToImageFilter< itk::Image< itk::Vector< double, 3 >, 3 >, itk::Image< itk::CovariantVector< double, 3 >, 3 > >
itkStrainImageFilter: warning(4): ITK type not wrapped, or currently not known: itk::ImageToImageFilter< itk::Image< itk::Vector< double, 4 >, 4 >, itk::Image< itk::CovariantVector< double, 4 >, 4 > >
[12/20] Generating .pyi files for Python wrapper interface
[13/20] Generating itkTransformToStrainFilterPython.cpp, ../../../../../../ITK-cp37-cp37m-manylinux2014_x64/Wrapping/Generators/Python/itk/itkTransformToStrainFilterPython.py
[14/20] Generating itkStrainImageFilterPython.cpp, ../../../../../../ITK-cp37-cp37m-manylinux2014_x64/Wrapping/Generators/Python/itk/itkStrainImageFilterPython.py
[15/20] Generating StrainPython.cpp, ../../../../../../ITK-cp37-cp37m-manylinux2014_x64/Wrapping/Generators/Python/itk/StrainPython.py
[16/20] Building CXX object Wrapping/Modules/Strain/CMakeFiles/StrainPython.dir/StrainPython.cpp.o
[17/20] Building CXX object Wrapping/Modules/Strain/CMakeFiles/StrainPython.dir/itkTransformToStrainFilterPython.cpp.o
[18/20] Building CXX object Wrapping/Modules/Strain/CMakeFiles/StrainPython.dir/itkStrainImageFilterPython.cpp.o
[19/20] Linking CXX shared module ../../../ITK-cp37-cp37m-manylinux2014_x64/Wrapping/Generators/Python/itk/_StrainPython.so
/work/include/itkTransformToStrainFilter.hxx: In member function ‘DynamicThreadedGenerateData’:
/work/include/itkTransformToStrainFilter.hxx:86:42: warning: iteration 3 invokes undefined behavior [-Waggressive-loop-optimizations]
   86 |       outputPixel(i, i) = jacobian(i, i) - static_cast<TOutputValue>(1);
      |                                          ^
/work/include/itkTransformToStrainFilter.hxx:76:32: note: within this loop
   76 |     for (unsigned int i = 0; i < ImageDimension; ++i)
      |                                ^
/work/include/itkTransformToStrainFilter.hxx: In member function ‘DynamicThreadedGenerateData’:
/work/include/itkTransformToStrainFilter.hxx:86:42: warning: iteration 3 invokes undefined behavior [-Waggressive-loop-optimizations]
   86 |       outputPixel(i, i) = jacobian(i, i) - static_cast<TOutputValue>(1);
      |                                          ^
/work/include/itkTransformToStrainFilter.hxx:76:32: note: within this loop
   76 |     for (unsigned int i = 0; i < ImageDimension; ++i)
      |                                ^
/work/include/itkTransformToStrainFilter.hxx: In member function ‘DynamicThreadedGenerateData’:
/work/include/itkTransformToStrainFilter.hxx:86:42: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations]
   86 |       outputPixel(i, i) = jacobian(i, i) - static_cast<TOutputValue>(1);
      |                                          ^
/work/include/itkTransformToStrainFilter.hxx:76:32: note: within this loop
   76 |     for (unsigned int i = 0; i < ImageDimension; ++i)
      |                                ^
/work/include/itkTransformToStrainFilter.hxx:111:51: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations]
  111 |               outputPixel(j, k) += jacobian(i, j) * jacobian(i, k) / static_cast<TOutputValue>(2);
      |                                                   ^
/work/include/itkTransformToStrainFilter.hxx:105:36: note: within this loop
  105 |         for (unsigned int i = 0; i < ImageDimension; ++i)
      |                                    ^
/work/include/itkTransformToStrainFilter.hxx:135:51: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations]
  135 |               outputPixel(j, k) -= jacobian(i, j) * jacobian(i, k) / static_cast<TOutputValue>(2);
      |                                                   ^
/work/include/itkTransformToStrainFilter.hxx:129:36: note: within this loop
  129 |         for (unsigned int i = 0; i < ImageDimension; ++i)
      |                                    ^
/work/include/itkTransformToStrainFilter.hxx: In member function ‘DynamicThreadedGenerateData’:
/work/include/itkTransformToStrainFilter.hxx:86:42: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations]
   86 |       outputPixel(i, i) = jacobian(i, i) - static_cast<TOutputValue>(1);
      |                                          ^
/work/include/itkTransformToStrainFilter.hxx:76:32: note: within this loop
   76 |     for (unsigned int i = 0; i < ImageDimension; ++i)
      |                                ^
/work/include/itkTransformToStrainFilter.hxx:111:51: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations]
  111 |               outputPixel(j, k) += jacobian(i, j) * jacobian(i, k) / static_cast<TOutputValue>(2);
      |                                                   ^
/work/include/itkTransformToStrainFilter.hxx:105:36: note: within this loop
  105 |         for (unsigned int i = 0; i < ImageDimension; ++i)
      |                                    ^
/work/include/itkTransformToStrainFilter.hxx:135:51: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations]
  135 |               outputPixel(j, k) -= jacobian(i, j) * jacobian(i, k) / static_cast<TOutputValue>(2);
      |                                                   ^
/work/include/itkTransformToStrainFilter.hxx:129:36: note: within this loop
  129 |         for (unsigned int i = 0; i < ImageDimension; ++i)
      |                                    ^
/work/include/itkTransformToStrainFilter.hxx: In member function ‘DynamicThreadedGenerateData’:
/work/include/itkTransformToStrainFilter.hxx:86:42: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations]
   86 |       outputPixel(i, i) = jacobian(i, i) - static_cast<TOutputValue>(1);
      |                                          ^
/work/include/itkTransformToStrainFilter.hxx:76:32: note: within this loop
   76 |     for (unsigned int i = 0; i < ImageDimension; ++i)
      |                                ^
/work/include/itkTransformToStrainFilter.hxx: In member function ‘DynamicThreadedGenerateData’:
/work/include/itkTransformToStrainFilter.hxx:86:42: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations]
   86 |       outputPixel(i, i) = jacobian(i, i) - static_cast<TOutputValue>(1);
      |                                          ^
/work/include/itkTransformToStrainFilter.hxx:76:32: note: within this loop
   76 |     for (unsigned int i = 0; i < ImageDimension; ++i)
      |                                ^