chore: use Java 21 for release test

Author: vlsi

.github/workflows/release-test.yml

@@ -29,7 +29,7 @@ jobs:
     - name: 'Set up JDK 11'
       uses: actions/setup-java@v4
       with:
-        java-version: 11
+        java-version: 21
         distribution: 'zulu'
     - name: 'Start release environment'
       run: |
@@ -75,7 +75,7 @@ jobs:
     - name: 'Set up JDK 11'
       uses: actions/setup-java@v4
       with:
-        java-version: 11
+        java-version: 21
         distribution: 'zulu'
     - name: 'Start release environment'
       run: |
@@ -121,7 +121,7 @@ jobs:
     - name: 'Set up JDK 11'
       uses: actions/setup-java@v4
       with:
-        java-version: 11
+        java-version: 21
         distribution: 'zulu'
     - name: 'Start release environment'
       run: |
@@ -167,7 +167,7 @@ jobs:
     - name: 'Set up JDK 8'
       uses: actions/setup-java@v4
       with:
-        java-version: 8
+        java-version: 21
         distribution: 'zulu'
     - name: 'Start release environment'
       run: |
@@ -213,7 +213,7 @@ jobs:
     - name: 'Set up JDK 8'
       uses: actions/setup-java@v4
       with:
-        java-version: 8
+        java-version: 21
         distribution: 'zulu'
     - name: 'Start release environment'
       run: |