Change CI build toolchains to JDK 8 + 21 versions.

Signed-off-by: Sjoerd Talsma <[email protected]>

.github/mvn-toolchains.xml

@@ -14,10 +14,10 @@
     <toolchain>
         <type>jdk</type>
         <provides>
-            <version>11</version>
+            <version>21</version>
         </provides>
         <configuration>
-            <jdkHome>${env.JAVA_11_HOME}</jdkHome>
+            <jdkHome>${env.JAVA_21_HOME}</jdkHome>
         </configuration>
     </toolchain>
 </toolchains>

.github/workflows/ci-build.yml

@@ -29,18 +29,16 @@ jobs:
         run: sudo apt-get install graphviz
       - name: Set up JDK 8 for compilation
         id: setup-java-8
-        uses: actions/setup-java@v3
+        uses: actions/setup-java@v4
         with:
           distribution: 'zulu'
           java-version: 8
-          java-package: jdk
-      - name: Set up JDK 11 for decent Javadoc
-        id: setup-java-11
-        uses: actions/setup-java@v3
+      - name: Set up JDK 21
+        id: setup-java-21
+        uses: actions/setup-java@v4
         with:
           distribution: 'zulu'
-          java-version: 11
-          java-package: jdk
+          java-version: 21
       - name: Setup maven cache
         uses: actions/cache@v3
         with:
@@ -52,7 +50,7 @@ jobs:
         shell: bash
         env:
           JAVA_8_HOME: ${{ steps.setup-java-8.outputs.path }}
-          JAVA_11_HOME: ${{ steps.setup-java-11.outputs.path }}
+          JAVA_21_HOME: ${{ steps.setup-java-21.outputs.path }}
           MAVEN_CLI_OPTS: --settings .github/mvn-settings.xml --global-toolchains .github/mvn-toolchains.xml
           GPG_EXECUTABLE: /usr/bin/gpg
           GPG_KEYNAME: ${{ secrets.GPG_KEYNAME }}
@@ -85,11 +83,10 @@ jobs:
           git config user.email "[email protected]"
       - name: Set up JDK
         if: env.GH_TOKEN != null
-        uses: actions/setup-java@v3
+        uses: actions/setup-java@v4
         with:
           distribution: 'zulu'
-          java-version: 11
-          java-package: jdk
+          java-version: 21
       - name: Set up maven cache
         if: env.GH_TOKEN != null
         uses: actions/cache@v3