Fix to load the swiftsim snapshot by removing the unused "RuntimePars"

[weiguangcui]

PR Summary

PR Checklist

• New features are documented, with docstrings and narrative docs
• Adds a test for any bugs fixed. Adds tests for new features.

[neutrinoceros]

Hi. In #4921 we tried to make sure this bit of code stayed backward compatible and improved forward compatibility. As far as I can tell what you're proposing here is to rip off the backward compatibility layer. Can you explain exactly what is not currently working with the main branch yet ?

[neutrinoceros]

(granted #4921 is not released yet so I don't expect yt 4.3.1 to work, but the dev branch should)

[weiguangcui]

Hi. In #4921 we tried to make sure this bit of code stayed backward compatible and improved forward compatibility. As far as I can tell what you're proposing here is to rip off the backward compatibility layer. Can you explain exactly what is not currently working with the main branch yet ?

Hi, sorry for forgetting to reply to this question. Yes, the new swift snapshot doesn't include that ["RuntimePars"] in its snapshot anymore. So it is removed, as such the "periodic" parameter is reading from another place: periodic = int(parameters["InitialConditions:periodic"])

[neutrinoceros]

@weiguangcui I still expect you shouldn't have any issue with the development branch. Have you tried installing it ?

python -m pip install git+https://github.com/yt-project/yt.git

If I'm right then your proposed patch is unnecessary. And if something else still needs fixing we need to take care of backward compatibility too, which is currently missing from your approach.