[24.2] Make k8s user and group ids overriddable per job

[nuwang]

Makes k8s user and group ids overridable per job, which was preventing some tools like ITs and data managers from running.

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.

[afgane]

Tested this in a dev env and works as expected now. The only potential addition would be to add an example somewhere of how to configure this option.