Skip tests on the -doc branches

[QuLogic]

PR Summary

GitHub Actions tests are already disabled for direct pushes, but not for the PRs directed at -doc branches. Azure is not disabled in any case. I'm not sure if I have that config right though.

PR Checklist

Tests and Styling

• [n/a] Has pytest style unit tests (and pytest passes).
• Is Flake 8 compliant (install flake8-docstrings and run flake8 --docstring-convention=all).

Documentation

• [n/a] New features are documented, with examples if plot related.
• [n/a] New features have an entry in doc/users/next_whats_new/ (follow instructions in README.rst there).
• [n/a] API changes documented in doc/api/next_api_changes/ (follow instructions in README.rst there).
• [n/a] Documentation is sphinx and numpydoc compliant (the docs should build without error).

[tacaswell]

We won't see if this works until we do the backport right?

[QuLogic]

Unfortunately not, as from the branch logs, it still ran.

I've found a regex for validating branch names in a vscode extension, and it doesn't seem like stuff like [] is allowed.

I have thus directly pushed v*-doc to v3.5.1-doc, which seems to have worked (see branch log above).