[ci] Add flake8 linting

This commit adds flake8 to the continuous integration (CI) pipeline.
flake8 will now run on every push and pull request, helping to enforce
code style consistency and identify potential issues early.  This will
improve code quality and maintainability.

Author: Ana06

Diff for: .github/workflows/linter.yml

@@ -13,9 +13,13 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Install dependencies
-        run: pip install black isort
+        run: pip install black isort flake8
+      # Different line limits: Black/isort (120), Flake8 (150). 
+      # Flake8 allows longer lines for better long string readability. Black doesn't enforce string length.
       - name: Run black
         run: black --line-length=120 --check --diff .
+      - name: Run flake8
+        run: flake8 --max-line-length 150
       - name: Run isort
         run: isort --check --diff --line-length 120 .