fix GitHub Workflows

Author: whilein

.github/workflows/deploy.yml

@@ -15,7 +15,7 @@ jobs:
         with:
           java-version: 21
       - name: Cache local Maven repository
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: ~/.m2/repository
           key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}