AthConfigFlags: restrict --filesInput to comma-separated list
Currently we support the following syntax for --filesInputs
:
--filesInput file1 file2
--filesInput file1,file2
Change this to only support the second version as was the case in legacy athena. This also simplifies the command line parsing and avoids swallowing flags.
I am not aware of any places where the first syntax is used, but if it is, the jobs should fail with an error immediately. Will ultimately sweep this to 24.0 as well.