ci: add pre-commit job

.gitlab-ci.yml

@@ -6,6 +6,21 @@ stages:
 variables:
   LATEST_VERSION_URL: https://docs.funkwhale.audio/latest.txt
 
+pre-commit:
+  stage: test
+  image: python:3.11
+  variables:
+    PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
+    PRE_COMMIT_HOME: "$CI_PROJECT_DIR/.cache/pre-commit"
+  cache:
+    paths:
+      - $CI_PROJECT_DIR/.cache/pip
+      - $CI_PROJECT_DIR/.cache/pre-commit
+  before_script:
+    - pip3 install pre-commit
+  script:
+    - pre-commit run --all --color=always --show-diff-on-failure
+
 test-install-script:
   stage: test
   image: $TEST_IMAGE