Bump Java to 25 for teku builds

Teku master upgraded its targetJavaVersion to Java 25, so the
install-deps action needs to provide a matching JDK or the
gradle build fails.

Author: claude

.github/actions/install-deps/action.yml

@@ -16,7 +16,7 @@ runs:
     if: contains(inputs.repository, 'teku')
     with:
       distribution: 'temurin'
-      java-version: '21'
+      java-version: '25'
   - uses: actions/setup-java@be666c2fcd27ec809703dec50e508c2fdc7f6654 # v5.2.0
     if: contains(inputs.repository, 'besu')
     with: