Fix TRT EP allocator memory leak

[chilo-ms]

Fix memory leak issue which comes from TRT EP's allocator object not being released upon destruction.
Following is the log from valgrind:

==1911860== 100,272 (56 direct, 100,216 indirect) bytes in 1 blocks are definitely lost in loss record 1,751 of 1,832
==1911860==    at 0x483CFA3: operator new(unsigned long) (vg_replace_malloc.c:472)
==1911860==    by 0x315DC2: std::_MakeUniq<onnxruntime::OrtAllocatorImplWrappingIAllocator>::__single_object std::make_unique<onnxruntime::OrtAllocatorImplWrappingIAllocator, std::shared_ptr<onnxruntime::IAllocator> >(std::shared_ptr<onnxruntime::IAllocator>&&) (unique_ptr.h:857)
==1911860==    by 0x30EE7B: OrtApis::KernelContext_GetAllocator(OrtKernelContext const*, OrtMemoryInfo const*, OrtAllocator**) (custom_ops.cc:121)
==1911860==    by 0x660D115: onnxruntime::TensorrtExecutionProvider::Compile(std::vector<onnxruntime::IExecutionProvider::FusedNodeAndGraph, std::allocator<onnxruntime::IExecutionProvider::FusedNodeAndGraph> > const&, std::vector<onnxruntime::NodeComputeInfo, std::allocator<onnxruntime::NodeComputeInfo> >&)::{lambda(void*, OrtApi const*, OrtKernelContext*)#3}::operator()(void*, OrtApi const*, OrtKernelContext*) const (tensorrt_execution_provider.cc:2223)

This issue happens after this EP allocator refactor