[red-knot] Add metrics collection

[dcreager]

This adds metrics collection to red-knot.

[rendered README]

Work in progress

[dcreager]

I still want to add more actual metrics (and verify that there aren't any performance regressions), but I'm pushing this up for visibility.

Overview documentation available in the README.

Collect metrics by passing the --metrics flag:

$ ./red_knot check --project ~/git/py/black --venv-path .venv --extra-search-path src --metrics

Then generate some graphs!

Total scopes created over time:

$ uv run crates/ruff_metrics/plot_metrics.py counter semantic_index.scope_count

Total scopes over time, per file:

$ uv run crates/ruff_metrics/plot_metrics.py counter semantic_index.scope_count --group-by file

Histogram of total scopes per file:

$ uv run crates/ruff_metrics/plot_metrics.py histogram semantic_index.scope_count --group-by file

[github-actions]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

Formatter (stable)

✅ ecosystem check detected no format changes.

Formatter (preview)

✅ ecosystem check detected no format changes.