Adding upstream version 1.31.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

.github/workflows/lint.yml

@@ -0,0 +1,30 @@
+name: lint
+
+on:
+  pull_request:
+    paths-ignore:
+      - '**.md'
+      - 'AUTHORS'
+
+jobs:
+  linters:
+    name: Linters
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out Git repository
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+        # todo
+        # remember to sync the ruff-check version number with pyproject.toml
+        # - name: Run ruff check
+        #   uses: astral-sh/ruff-action@9828f49eb4cadf267b40eaa330295c412c68c1f9 # v3.2.2
+        #   with:
+        #     version: 0.11.5
+
+        # remember to sync the ruff-check version number with pyproject.toml
+      - name: Run ruff format
+        uses: astral-sh/ruff-action@9828f49eb4cadf267b40eaa330295c412c68c1f9 # v3.2.2
+        with:
+          version: 0.11.5
+          args: 'format --check'