workflows: open-code pre-commit check

The pre-commit action is in maintenance mode, and is easily replicated.

Signed-off-by: Benjamin Gilbert <bgilbert@cs.cmu.edu>

Author: bgilbert

.github/workflows/validate.yml

@@ -20,5 +20,12 @@ jobs:
         uses: actions/setup-python@v6
         with:
           python-version: '3.12'
+      - name: Install dependencies
+        run: python -m pip install pre-commit
+      - name: Cache pre-commit environments
+        uses: actions/cache@v4
+        with:
+          key: pre-commit|${{ env.pythonLocation }}|${{ hashFiles('.pre-commit-config.yaml') }}
+          path: ~/.cache/pre-commit
       - name: Run pre-commit hooks
-        uses: pre-commit/action@v3.0.1
+        run: pre-commit run -a --show-diff-on-failure --color=always