Updated action dependencies.

Added 21 java version support

.github/workflows/test-pr.yml

@@ -7,16 +7,18 @@ on:
 jobs:
   build:
     name: Checkout and Build
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
+    continue-on-error: true
 
     strategy:
+      fail-fast: false
       matrix:
-        java-version: [8, 11, 16, 17]
+        java-version: [8, 11, 16, 17, 21]
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: JDK setup
-        uses: actions/setup-java@v2
+        uses: actions/setup-java@v4
         with:
           java-version: ${{ matrix.java-version }}
           distribution: 'temurin'
@@ -26,10 +28,10 @@ jobs:
 
   coverage:
     name: Quality Assurance
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     needs: [ build ]
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Codacy analysis reporting
         uses: codacy/codacy-analysis-cli-action@master

README.md

@@ -28,7 +28,7 @@ Quick Start
 
 In order to build this project you'll need:
 
- * Java 8 - 17, which can be downloaded [from Oracle](https://www.oracle.com/technetwork/java/javase/downloads/index.html), or for Linux users [OpenJDK](https://openjdk.java.net/install/index.html).
+ * Java 8 - 21, which can be downloaded [from Oracle](https://www.oracle.com/technetwork/java/javase/downloads/index.html), or for Linux users [OpenJDK](https://openjdk.java.net/install/index.html).
  * [Maven v3+](https://maven.apache.org/)
 
 ### Building the veraPDF Validation Model