Enable mypy parallel workers in pre-commit.

[adamtheturtle]

Summary

• run the mypy pre-push hook with --num-workers=4 to enable parallel workers
• run mypy-docs via doccmd with a command string that also includes --num-workers=4

Test plan

• pre-commit hooks run successfully on commit (including yamlfix)
• uv run --extra=dev -m mypy --num-workers=4 (executes; currently hits existing mypy internal error in repo)

Made with Cursor

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Note

Low Risk
Low risk config-only change that only affects local pre-push type-checking execution; main impact is potential nondeterminism/perf differences in mypy output.

Overview
Updates the pre-push pre-commit hooks to run mypy with --num-workers=4, enabling parallel type-checking.

Also adjusts the mypy-docs doccmd invocation so the embedded mypy command includes the same --num-workers=4 flag.

^{Reviewed by Cursor Bugbot for commit 2d87cce. Bugbot is set up for automated code reviews on this repo. Configure here.}