ci: cache mypy to speed up runs (#48)

Author: sdn4z

.github/workflows/lint.yml

@@ -21,6 +21,15 @@ jobs:
       - name: Install the project
         run: uv sync --locked --extra lint --extra test
 
+      - name: Cache mypy cache
+        uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684 # v4.2.1
+        with:
+          path: .mypy_cache
+          key: mypy-${{ runner.os }}
+          retention-days: 30
+          restore-keys: |
+            mypy-${{ runner.os }}
+
       - name: Lint
         run: |
           uv run ruff format --check src tests eval