Upgrade github action to setup-java@v4

Author: Stefan Hahmann

.github/workflows/build-main.yml

@@ -14,7 +14,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Set up Java
-        uses: actions/setup-java@v2
+        uses: actions/setup-java@v4
         with:
           java-version: '8'
           distribution: 'zulu'

.github/workflows/build-pr.yml

@@ -12,7 +12,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Set up Java
-        uses: actions/setup-java@v2
+        uses: actions/setup-java@v4
         with:
           java-version: '8'
           distribution: 'zulu'