Update ci.yml

Author: xuwei-k

.github/workflows/ci.yml

@@ -11,8 +11,8 @@ jobs:
     strategy:
       fail-fast: false
     steps:
-    - uses: actions/checkout@v3
-    - uses: actions/setup-java@v3
+    - uses: actions/checkout@755da8c3cf115ac066823e79a1e1788f8940201b # v3.2.0
+    - uses: actions/setup-java@1df8dbefe2a8cbc99770194893dd902763bee34b # v3.9.0
       with:
         java-version: 8
         distribution: temurin