Update ghaction away from flake8 to ruff

Author: ksunden

.github/workflows/flake8.yml renamed to .github/workflows/ruff.yml

@@ -1,4 +1,4 @@
-name: Check Code Style - FLAKE8
+name: Check Code Style - ruff
 
 on: [push, pull_request]
 
@@ -15,7 +15,7 @@ jobs:
           # installation problems if out of date.
           python -m pip install --upgrade pip setuptools numpy
 
-          pip install flake8
-      - name: Run flake8
+          pip install ruff
+      - name: Run ruff
         run: |
-          flake8
+          ruff check