Update chart linting Python version as 3.7 is removed.

Author: alowde

.github/workflows/lint-test.yaml

@@ -18,7 +18,7 @@ jobs:
 
       - uses: actions/setup-python@v6
         with:
-          python-version: 3.7
+          python-version: 3.8
 
       - name: Set up chart-testing
         uses: helm/chart-testing-action@v2.7.0