cicd: add java cache

To speedup pipeline and reduce it's cost it would be better to cache
maven dependancies.

Author: dkropachev

.github/workflows/pr-verify.yml

@@ -16,6 +16,7 @@ jobs:
         with:
           distribution: 'temurin'
           java-version: '11'
+          cache: maven
       - name: Maven verify
         run: mvn -B verify