Updated build to run using ubuntu-latest and JDK 21

Author: svenar-nl

.github/workflows/build.yml

@@ -10,7 +10,15 @@ on:
 
 jobs:
   build:
-    uses: ResilientGroup/MavenSetup/.github/workflows/build.yml@1.9.0
-    with:
-      javadoc-project-name: PowerCamera
-    secrets: inherit
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up JDK 21
+      uses: actions/setup-java@v3
+      with:
+        java-version: '21'
+        distribution: 'temurin'
+        cache: maven
+    - name: Build with Maven
+      run: mvn -B package --file pom.xml