Fix sync recipes and add base justfile

[redsun82]

Both the justfile and the pre-commit configuration for the pr-check sync were broken:

• justfiles run recipes one line at a time in a fresh shell, so the venv activation was not working
• the pre-commit config was relying on an installed ruamel.yaml pakcage, but the default one installable via apt on Ubuntu 24.04 is old and generates different output (with formatting differences).

Now:

• the venv dance is put in a separate bash script
• both just and pre-commit will use that same script, so both problems will be fixed

As a bonus, a root justfile is added exposing the update-pr-checks recipes plus a build one. Running just without arguments will also now call the default sync recipes that will call both of the above.

Merge / deployment checklist

• Confirm this change is backwards compatible with existing workflows.
• Confirm the readme has been updated if necessary.
• Confirm the changelog has been updated if necessary.

[Copilot]

PR Overview

This PR aims to fix issues related to the sync recipes in both justfiles and the pre-commit configuration by switching from a Python script to a shared bash script for activating the virtual environment and running the recipes.

• Update the pre-commit configuration to use the new bash script (pr-checks/sync.sh)
• Ensure that both just and pre-commit hooks use a unified venv activation mechanism for consistent behavior

Changes

File	Description
.pre-commit-config.yaml	Changed the hook entry from python3 pr-checks/sync.py to pr-checks/sync.sh to use the shared bash script

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

.pre-commit-config.yaml:19

• Ensure that the pr-checks/sync.sh script is executable and includes a proper shebang so that it runs as intended under the system language.

entry: pr-checks/sync.sh

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[NlightNFotis]

Thank you for fixing the justfile.

I seem to recall it working locally when I was last working on this a few months ago, but it might have been incidental?

[NlightNFotis]

Would it be possible to add a comment on top of the command?

Because we're probably going to forget which one is which after a couple months, so just --list will probably be our fallback then, and it renders the comment as inline help when invoked.

[redsun82]

Good point!

[NlightNFotis]

(Reapproving after review automatically went stale).

Thanks for your work on this @redsun82 , I appreciate it 👍🏻

[redsun82]

Thank you for fixing the justfile.

I seem to recall it working locally when I was last working on this a few months ago, but it might have been incidental?

@NlightNFotis Yeah, thinking back that was working because:

• on macOS, sh is actually an alias of bash (I'm on Linux where that's not the case)
• you had the proper package available to python3 outside of the venv, so the last command was also working despite being run outside of the venv