Pin external GitHub actions with git hash

Signed-off-by: Yi Chen <[email protected]>

Author: ChenYi015

.github/workflows/ci.yml

@@ -60,7 +60,7 @@ jobs:
           fetch-depth: 0
 
       - name: Set up Helm
-        uses: azure/setup-helm@v4.3.0
+        uses: azure/setup-helm@1a275c3b69536ee54be43f2070a358922e12c8d4
         with:
           version: v3.17.3
 
@@ -71,7 +71,7 @@ jobs:
         run: helm unittest ${{ env.HELM_CHART_DIR }}/${{ env.FLINK_OPERATOR_CHART }} --file "tests/**/*_test.yaml" --strict --debug
 
       - name: Set up chart-testing
-        uses: helm/chart-testing-action@v2.7.0
+        uses: helm/chart-testing-action@0d28d3144d3a25ea2cc349d6e59901c4ff469b3b
 
       - name: Run chart-testing (list-changed)
         id: list-changed