Update runners to ubuntu-24.04 from deprecated ubuntu-20.04 label

Author: billnapier

.github/workflows/python-tests.yaml

@@ -44,7 +44,7 @@ jobs:
         matrix:
           tox-environment: [ "lint" ]
       name: ${{ matrix.tox-environment }}
-      runs-on: ubuntu-20.04
+      runs-on: 'ubuntu-24.04'
       steps:
         - name: Checkout Contrib Repo @ SHA - ${{ github.sha }}
           uses: actions/checkout@v2