Run SonarCloud analysis on Java 21 (SonarQube Cloud dropped Java 17)

SonarQube Cloud stopped supporting Java 17 as a scanner runtime on
2026-07-20 and now requires Java 21+. The Sonar workflows pin Java 17, so
the "Sonar Scanner" job on master started failing, which froze the
SonarCloud analysis at its 2026-07-18 snapshot and kept the Quality Gate
red for a finding that is already fixed on master.

Bump the JVM that runs the analysis (mvn -Pjacoco,sonar) from 17 to 21 in
sonar.yml and sonar-pr-analysis-publish.yml.

This changes only the JVM used to run the analysis in CI. The plugin's
compile target stays Java 8 (maven-compiler-plugin source/target 8) and the
user-facing test matrix (Java 8/11) is unchanged. A full build and test run
passes on Temurin 21 locally (976 tests, 0 failures).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: 2 people

.github/workflows/sonar-pr-analysis-publish.yml

@@ -28,10 +28,10 @@ jobs:
       GITHUB_REPO: ${{ github.repository }}
       SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
     steps:
-      - name: Setup Java 17 # Move Sonar analysis to Java 17
+      - name: Setup Java 21 # SonarQube Cloud requires Java 21+ to run the analysis
         uses: actions/setup-java@v5
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'temurin'
       - name: Dump GitHub context
         run: echo '${{ toJSON(github.event) }}'

.github/workflows/sonar.yml

@@ -29,10 +29,10 @@ jobs:
         with:
           # Shallow clones should be disabled for a better relevancy of analysis
           fetch-depth: 0
-      - name: Setup Java 17 # Move Sonar analysis to Java 17
+      - name: Setup Java 21 # SonarQube Cloud requires Java 21+ to run the analysis
         uses: actions/setup-java@v5
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'temurin'
       - name: Maven Sonar
         run: ./mvnw ${MAVEN_ARGS} -Pjacoco,sonar clean install