MNT: drop unused pre-commit (the package) dependency - #32407

PR summary

We have moved to prek but this got missed in the migration. This PR:

• changes the depnedency in pyproject.toml to prek (matches our docs and CI runs)
• clarified a title that "pre-commit" means "git's pre-commit" not "pre-commit the confusingly named project that provides pre-commit hooks".
• adjusts the in-line install suggestion to pixi or uv's global tool invocations (things can break in weird ways if you install prek from a virtual env that you later clean up)

AI Disclosure

None

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