Update to new version of python net

[sm6srw]

Purpose

This PR will bump pythonnet to version 2.5.1.7. This is related to DYN-3476.

Declarations

Check these if you believe they are true

• The codebase is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning and are documented in the API Changes document.
• This PR modifies some build requirements and the readme is updated

[mjkkirschner]

@sm6srw what about the references to Python.Included:

Dynamo/src/Libraries/DSCPython/DSCPython.csproj

Line 43 in fddfe07

<Reference Include="Python.Included, Version=2.5.0.0, Culture=neutral, processorArchitecture=MSIL">

also I may have lead you astray - do we also need to update the python.Runtime.dll? Where is that coming from?

reference here:

Dynamo/src/Libraries/DSCPython/DSCPython.csproj

Line 47 in fddfe07

<Reference Include="Python.Runtime, Version=2.4.1.0, Culture=neutral, processorArchitecture=MSIL">

[mjkkirschner]

see above comment about other references in the DSCPython project.

[sm6srw]

see above comment about other references in the DSCPython project.

It works without changing them (they are both out of sync as it is already) but I will go ahead and update them.
I searched for the old reference, now I know why I only found a reference in test project.
Thanks for catching this.