ci: use Python 3.12 for pre-commit

This should make it consistent with pre-commit.ci service.

See #1434

.github/workflows/pre-commit.yml

@@ -29,7 +29,7 @@ jobs:
     - name: Setup Python
       uses: actions/setup-python@v5
       with:
-        python-version: '3.11'
+        python-version: '3.12'
     - name: Install uv
       run: curl -LsSf https://astral.sh/uv/install.sh | sh
     - name: Install dependencies