[24.0] Add input extra files to get_input_fnames

[mvdbeek]

This should fix volume mounts in kubernetes,
which calls:

volume_mounts.extend(generate_relative_mounts(data_claim, job_wrapper.job_io.get_input_fnames()))

The only other consumers are pbs, using an undocument config option (ahem ...).

How to test the changes?

(Select all options that apply)

• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

• I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.

[ksuderman]

Thanks Marius. I've tested this and it solves the problem we were looking at in Brno.

[mvdbeek]

Awesome, thanks for checking!