FindFastJet.cmake CentOS 9 Compatibility Fix, master branch (2022.07.04.)
Re-wrote the logic of adding gfortran to the library list together with the FastJet libraries.
When using the compiler from /usr the previous logic (of looking for the Fortran library in $LD_LIBRARY_PATH) was not successful. So now I'm rather picking it up by checking the value of ${CMAKE_Fortran_COMPILER_ID}.
Note that I'm not super happy with this setup either, this is still pretty fragile. But I couldn't come up with anything more robust. 
This is meant to fix ATLJETMET-1435, and be one more step towards ATLINFR-4547.
