Switch to Java 21

Next release will require Java 21. Switch to it.

JIRA: LIGHTY-327
Signed-off-by: Ivan Hrasko <ivan.hrasko@pantheon.tech>

Author: ihrasko

.github/workflows/build.yml

@@ -20,10 +20,10 @@ jobs:
       SONAR_PROJECT_KEY: ${{ secrets.SONAR_PROJECT_KEY}}
     steps:
       - uses: actions/checkout@v2
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v3
         with:
-          java-version: 17
+          java-version: 21
           distribution: 'temurin'
       - name: Cache SonarCloud packages
         uses: actions/cache@v1
@@ -44,7 +44,7 @@ jobs:
       - name: Maven install + Test + SonarCloud
         if: ${{ env.SONAR_TOKEN != 0 }}
         run: mvn clean install org.sonarsource.scanner.maven:sonar-maven-plugin:sonar
-          -Dsonar.java.source=17
+          -Dsonar.java.source=21
           -Dsonar.projectKey=${{ env.SONAR_PROJECT_KEY }}
           -Dsonar.organization=${{ env.SONAR_ORGANIZATION }}
           -Dsonar.host.url=https://sonarcloud.io

README.md

@@ -11,7 +11,7 @@ you can create your own device. This device can be built with the use of builder
 adding custom YANG models, custom request processors & more.
 
 ## Build & Run
-* Build the project with Java 17:
+* Build the project with Java 21:
 ```
 mvn clean install
 ```