pin python 3.12 for publishing

[philvarner]

Related Issue(s):

• n/a

Proposed Changes:

1. The default python for gitlab changed to 3.13 recently, so the build-package in python-publish.yml gitlab command now fails because of the 3.12 constraint on the package. Explicitly pinning the publish to 3.12, with the expectation we will update to support 3.13 sometime soon.

PR Checklist:

• I have added my changes to the CHANGELOG or a CHANGELOG entry is not required.

[trevorskaggs]

Do we need a ticket for the 3.13 upgrade? Otherwise this looks good to go!

[jkeifer]

I'd actually go the other way around on this and fix the pinning and add testing for 3.13. @pjhartzell already did this as part of #132. The strict pinning on 3.12 was, I believe, the result of miscommunication at the last STAPI sprint, not an intentional limitation restricting this package to 3.12.