Utilities/Doxygen/mcdoc.py chokes on non-existent include directory

[dzenanz]

    Start 1042: ITKIOMeshInDoxygenGroup

1042: Test command: "C:\Program Files\Python312\python.exe" "C:/Misc/ITK-patches2/CMake/../Utilities/Doxygen/mcdoc.py" "check" "ITKIOMesh" "C:/Misc/ITK-patches2/Modules/IO/Mesh/include"
1042: Working Directory: C:/Misc/ITK-patches2-vs22/Modules/IO/Mesh
1042: Test timeout computed to be: 1500
1042: Traceback (most recent call last):
1042:   File "C:\Misc\ITK-patches2\Utilities\Doxygen\mcdoc.py", line 195, in <module>
1042:     ret = main()
1042:           ^^^^^^
1042:   File "C:\Misc\ITK-patches2\Utilities\Doxygen\mcdoc.py", line 161, in main
1042:     ret = max(ret, checkGroup(fname, module))
1042:                    ^^^^^^^^^^^^^^^^^^^^^^^^^
1042:   File "C:\Misc\ITK-patches2\Utilities\Doxygen\mcdoc.py", line 85, in checkGroup
1042:     f = open(fname, encoding="utf-8")
1042:         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1042: FileNotFoundError: [Errno 2] No such file or directory: 'C:/Misc/ITK-patches2/Modules/IO/Mesh/include'
1/1 Test #1042: ITKIOMeshInDoxygenGroup ..........***Failed    0.08 sec