yamllint: more strict regex to capture only control files ending with .yml

Author: vojtapolasek

.github/workflows/ci_lint.yml

@@ -49,7 +49,7 @@ jobs:
       - name: Run yamllint in Control Files Modified by PR
         if: ${{ env.CONTROLS_CHANGES == 'true' }}
         run: |
-          for control_file in $(cat filenames.txt | grep "controls/"); do
+          for control_file in $(cat filenames.txt | grep "controls/.*\.yml"); do
             echo "Running yamllint on $control_file..."
             yamllint "$control_file"
           done