CI: rename codegen workflow to be more generic

Also remove the python setup stage as it shouldn't be necessary any more
seen that bazel uses a specific bundled one.

.github/workflows/python-tooling.yml

@@ -0,0 +1,32 @@
+name: Python tooling
+
+on:
+  pull_request:
+    paths:
+      - "misc/bazel/**"
+      - "misc/codegen/**"
+      - "misc/scripts/models-as-data/bulk_generate_mad.py"
+      - "*.bazel*"
+      - .github/workflows/codegen.yml
+      - .pre-commit-config.yaml
+    branches:
+      - main
+      - rc/*
+      - codeql-cli-*
+
+permissions:
+  contents: read
+
+jobs:
+  check-python-tooling:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: pre-commit/action@646c83fcd040023954eafda54b4db0192ce70507
+        name: Check that python code is properly formatted
+        with:
+          extra_args: black --all-files
+      - name: Run codegen tests
+        shell: bash
+        run: |
+          bazel test //misc/codegen/...