update workflow

.github/workflows/build.yml

@@ -5,29 +5,20 @@ on: [pull_request, push]
 
 jobs:
   build:
-    strategy:
-      matrix:
-        # Use these Java versions:
-        java: [
-            17
-        ]
-        os: [ubuntu-latest]
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
     steps:
       - name: checkout repository
         uses: actions/checkout@v3
       - name: validate gradle wrapper
         uses: gradle/wrapper-validation-action@v1
-      - name: setup jdk ${{ matrix.java }}
+      - name: setup jdk
         uses: actions/setup-java@v3
         with:
           distribution: 'temurin'
-          java-version: ${{ matrix.java }}
+          java-version: 21
       - name: build
         run: ./gradlew build
       - name: upload build artifacts
-        # We only want to generate & upload artifacts built on one OS
-        if: ${{ runner.os == 'Linux' && matrix.java == '17' }}
         uses: actions/upload-artifact@v3
         with:
           name: Artifacts