👷 Run Ruff linter on back-end pull requests

.woodpecker.yml

@@ -1,6 +0,0 @@
-pipeline:
-  first-job:
-    image: busybox
-    commands:
-      - echo "first run"
-

backend/.woodpecker/.lint.yaml

@@ -0,0 +1,9 @@
+steps:
+  - name: ruff
+    image: python:3.12-alpine
+    commands:
+      - pip install ruff
+      - ruff . --format github
+    when:
+      - event: pull_request
+        path: 'backend/**'