fix: update actions to v4 and java 21

.github/workflows/build.yml

@@ -9,28 +9,28 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - name: Checkout
-      uses: actions/checkout@v3
-
-    - name: Setup java 18
-      uses: actions/setup-java@v3
-      with:
-        distribution: 'temurin'
-        java-version: '18'
-        cache: 'maven'
-
-    - name: build
-      run: mvn clean package
-
-    - name: Extract Maven project version
-      run: echo "name=version::$(mvn help:evaluate -Dexpression=project.version -q -DforceStdout)" >> $GITHUB_OUTPUT
-      id: project
-
-    - name: List files
-      run: ls -la
-
-    - name: Upload Plugin jar
-      uses: actions/upload-artifact@v3
-      with:
-        name: "AnimVanish"
-        path: target/*.jar
+      - name: Checkout
+        uses: actions/checkout@v4.2.2
+
+      - name: Setup java 21
+        uses: actions/setup-java@v4.7.0
+        with:
+          distribution: 'temurin'
+          java-version: '21'
+          cache: 'maven'
+
+      - name: build
+        run: mvn clean package
+
+      - name: Extract Maven project version
+        run: echo "name=version::$(mvn help:evaluate -Dexpression=project.version -q -DforceStdout)" >> $GITHUB_OUTPUT
+        id: project
+
+      - name: List files
+        run: ls -la
+
+      - name: Upload Plugin jar
+        uses: actions/upload-artifact@v4.6.0
+        with:
+          name: "AnimVanish"
+          path: target/*.jar