Fix pre-commit PR check

[thomashampson]

Description of work

rstcheck is failing with exit code -11 after Python updated to 3.13 in the conda environment used for the pre-commit PR check. Here we pin to 3.12 to avoid the issue.

There is no associated issue.

To test:

Ensure rstcheck is run and passes in the PR check on Jenkins. Verify that python is pinned to 3.12 in the pre-commit conda environment.

This does not require release notes because it's a fix to a build script.

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[SilkeSchomann]

I can confirm that after pinning python to 3.12 in the pre-commit conda rstcheck passes.