Introduce a CI step to validate dependency locks

.github/workflows/ci.yml

@@ -94,3 +94,26 @@ jobs:
       - name: Lint
         run: |
           poetry run flake8 . --jobs=auto --format=github
+
+  validate-dependencies:
+    name: Check dependency locks
+    runs-on: ubuntu-20.04
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.9
+
+      - name: Set up Poetry
+        uses: abatilo/actions-poetry@v2.1.5
+        with:
+          poetry-version: 1.3.2
+
+      - uses: PeterJCLaw/validate-generated-files@v1
+        with:
+          command: poetry lock --no-update
+          files: poetry.lock