Fix post-release workflow

Author: trask

.github/workflows/release.yml

@@ -252,6 +252,14 @@ jobs:
             sleep 60
           done
 
+      - uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5.0.0
+        with:
+          distribution: temurin
+          java-version-file: .java-version
+
+      - name: Setup Gradle
+        uses: gradle/actions/setup-gradle@4d9f0ba0025fe599b4ebab900eb7f3a1d93ef4c2 # v5.0.0
+
       - name: Update apidiff baseline
         env:
           VERSION: ${{ needs.release.outputs.version }}