fix: linter python version not available error

Signed-off-by: Stella Alice Schlotter <stella.a.schlotter@gmail.com>

Author: efcy

.github/workflows/lint-test.yaml

@@ -21,7 +21,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.7
+          python-version: 3.7.17
 
       - name: Set up chart-testing
         uses: helm/chart-testing-action@v2.1.0