Set up Java 8 for opencode.

Author: LSantha

.github/workflows/opencode.yml

@@ -25,7 +25,11 @@ jobs:
         uses: actions/checkout@v6
         with:
           persist-credentials: false
-
+      - name: Set up JDK 8
+        uses: actions/setup-java@v4
+        with:
+          java-version: '8'
+          distribution: 'zulu'
       - name: Run opencode
         uses: anomalyco/opencode/github@latest
         env: