Workflow update

- Updated action dependencies
- Added 21 java version support
- Jobs don't fail on error

.github/workflows/test-pr.yml

@@ -7,16 +7,19 @@ 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: [11, 16, 17]
+        java-version: [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'

README.md

@@ -20,7 +20,7 @@ Pre-requisites
 
 In order to make use of the DSL support you'll require
 
- * Java 9 - 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 9 - 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).
  * The [Eclipse IDE](https://eclipse.org/) with the [Xtext plug-in](https://eclipse.org/Xtext/download.html). If you haven't installed Eclipse then we recommend downloading the [Xtext Eclipse distribution](https://eclipse.org/Xtext/download.html).
 
 Installation of DSL Support in Eclipse