Add check-lockfile workflow

.github/workflows/check-lockfile.yml

@@ -0,0 +1,35 @@
+name: Check lockfile
+
+on:
+  push:
+    paths-ignore:
+      - 'docs/**'
+      - '**/*.md'
+  pull_request:
+    paths-ignore:
+      - 'docs/**'
+      - '**/*.md'
+
+jobs:
+  check-lockfile:
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+          cache: 'pip'
+
+      - name: Install poetry
+        run: |
+          pipx install poetry
+
+      - name: Check lockfile
+        run: |
+          poetry check --lock