Add Java 21 build

Update to checkout@v4

Author: stefanseifert

.github/workflows/maven-build.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        java: [11, 17]
+        java: [11, 17, 21]
         os: [ubuntu-latest]
         distribution: [temurin]
         include:

.github/workflows/maven-deploy.yml

@@ -17,7 +17,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Configure GIT
         run: |

.github/workflows/release-from-tag.yml

@@ -12,7 +12,7 @@ jobs:
     permissions:
       contents: write
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: ncipollo/release-action@v1
       with:
         body: 'Changes: https://devops.wcm.io/conga/plugins/aem/changes-report.html'