fix(mypy): add fast and full mypy modes (#3975)

`mypy` became very slow for the common path. This can make local
pre-commit runs very slow. Let's restore that.

- restore fast mirrors-mypy hook for local runs
- add optional mypy-full hook and docs so devs can match CI
- run full mypy in CI with a hint when failures occur

### Test Plan
- uv run pre-commit run mypy --all-files
- uv run pre-commit run mypy-full --hook-stage manual --all-files
- uv run --group dev --group type_checking mypy

CONTRIBUTING.md

@@ -61,6 +61,18 @@ uv run pre-commit run --all-files -v
 
 The `-v` (verbose) parameter is optional but often helpful for getting more information about any issues with that the pre-commit checks identify.
 
+To run the expanded mypy configuration that CI enforces, use:
+
+```bash
+uv run pre-commit run mypy-full --hook-stage manual --all-files
+```
+
+or invoke mypy directly with all optional dependencies:
+
+```bash
+uv run --group dev --group type_checking mypy
+```
+
 ```{caution}
 Before pushing your changes, make sure that the pre-commit hooks have passed successfully.
 ```