Draft: Experiments with CI - #32538

PR summary

This is not a real PR, it is designed to allow me to run various experiences on the macOS 26 CI runners. Hopefully, I can figure out a way to make them faster.

AI Disclosure

I gave the following prompt to AI:

disable all actions except for python 3.14 on macos-26. Make do_not_merge always fail as an additional warning.

I then added comments and added a step to tests.yml to give me the size of "/opt" after Homebrew installs packages.

PR quality check

• Use an expressive title, e.g. "Fix title font property precedence"
• [/] New and changed code is tested
• [/] Plotting related features are demonstrated in an example
• [/] New features and API changes have release notes
• [/] Documentation complies with general and docstring guidelines