Development: introduce Ruff as linter/formatter (#3039)

.github/workflows/test-only.yml

@@ -8,13 +8,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Lint with flake8
+      - name: Lint with Ruff
         run: |
-          pip3 install flake8
-          # stop the build if there are Python syntax errors or undefined names
-          flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
-          # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
-          flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+          pip install ruff
+          # Check for syntax errors and undefined names
+          ruff check . --select E9,F63,F7,F82
+          # Complete check with errors treated as warnings
+          ruff check . --exit-zero
 
   test-application-3-10:
     needs: lint-code
@@ -41,5 +41,4 @@ jobs:
     uses: ./.github/workflows/test-stack-reusable-workflow.yml
     with:
       python-version: '3.13'
-      skip-pypuppeteer: true
-      
+      skip-pypuppeteer: true