Harden CI lint path for stable agent builds

Jenkinsfile

@@ -52,7 +52,7 @@ pipeline {
                     PIP_EXTRA_INDEX_URL=${PIP_EXTRA_INDEX_URL:-https://pypi.mandelblog.com/root/pypi/+simple/} \
                     pip install --no-build-isolation --pre --editable . setuptools wheel --upgrade --upgrade-strategy=eager --use-deprecated=legacy-resolver
                     cp "${JOB_BASE_NAME}/ocyan.json" "${JOB_BASE_NAME}/${JOB_BASE_NAME}.json"
-                    pip install pylint pylint-django vdt.versionplugin.wheel
+                    pip install ruff vdt.versionplugin.wheel
                     pip install --upgrade "setuptools==69.5.1" wheel
                     manage.py migrate --no-input --skip-checks
                     manage.py loaddemodata --skip-checks || true
@@ -66,8 +66,9 @@ pipeline {
                 sh '''
                     . .venv/bin/activate
                     pip install coverage
+                    pip install ruff
                     cat mandelstudio/ocyan.json | python3 -m json.tool 1>/dev/null
-                    pylint setup.py mandelstudio/
+                    make lint
                 '''
             }
         }