Python lib determination is not platform independent

[trittsv]

It uses python3 executable to determine the python libs, but on windows there is no python3.exe.
The windows python3 installer creates only python.exe.

See here:

cyclonedds/src/tools/idlc/src/idlc/generator.c

Line 167 in d7db65c

if (run_library_locator("python3 -m cyclonedds.__idlc__", &file) != 0) {

Of course a easy workaround is to duplicate the python.exe on windows and rename it to python3.exe ...

[eboasson]

What could go wrong if, on failure of the existing test, we simply tried again but using plain python? It would still need to have cyclonedds.__idlc__ available and so even if that causes it to start python 2 it seems to me it should be ok.