Make ROOT load libraries without the .so extension

[jmcarcell]

BEGINRELEASENOTES

• Make ROOT load libraries without the .so extension

ENDRELEASENOTES

See key4hep/EDM4hep#339 and key4hep/EDM4hep#338. This means no one is running the tests on MacOS 😄

[tmadlener]

Well, maybe someone has, but they ignored the failing tests ;)

There is another error message with an explicit .so here:

podio/python/podio/__init__.py

Line 10 in 1fc075d

print("Unable to load podio, make sure that libpodio.so is in LD_LIBRARY_PATH")

[jmcarcell]

I don't have a mac handy to check but maybe it doesn't matter because of

podio/CMakeLists.txt

Line 52 in 1fc075d

set(CMAKE_SHARED_LIBRARY_SUFFIX ".so")

[tmadlener]

Ah yes, that probably also affects mac OS builds. Not sure if mac OS still allows shared libs with .so ending though. Anyhow, for this PR it should not matter too much as long as ROOT does the "right thing".