Fix Ruff command in GitHub Actions workflow.

Author: james-ecd

.github/workflows/tests-and-linting.yml

@@ -29,7 +29,7 @@ jobs:
         poetry install
     - name: ruff
       run: |
-        poetry run ruff check --format=github .
+        poetry run ruff check .
     - name: Test with pytest
       run: |
         poetry run pytest --cov=flare_explorer --cov-report xml:coverage.xml