ci: updated CI workflow to Java 21 and added macos

Author: quintesse

.github/workflows/ci.yml

@@ -18,20 +18,18 @@ on:
 jobs:
   build:
 
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
 
     steps:
     - uses: actions/checkout@v5
-    - name: Set up JDK 11
+    - name: Set up JDK 21
       uses: actions/setup-java@v5
       with:
-        java-version: '11'
+        java-version: '21'
         distribution: 'temurin'
         cache: maven
     - name: Build with Maven
       run: mvn -B verify jreleaser:assemble -Prelease --file pom.xml
-
-    # Optional: Uploads the full dependency graph to GitHub to improve the quality of Dependabot alerts this repository can receive
-    - name: Update dependency graph
-      uses: advanced-security/maven-dependency-submission-action@df268dd1684fb95352aa463056e3cf41f9acb94b
-      if: github.event_name != 'pull_request'