Updated CI config

Author: sveinbjornt

.github/workflows/main.yml

@@ -23,7 +23,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-java@v3
+      - uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
           java-version: '17'
@@ -52,7 +52,7 @@ jobs:
         run: |
           bash build_apk.sh
       - name: Slack notification
-        uses: 8398a7/action-slack@v2
+        uses: 8398a7/action-slack@v3
         with:
           status: ${{ job.status }}
           author_name: Integration Testing