remove sonar workflow which works with jdk17+ only

.github/workflows/sonar.yml

@@ -1,26 +0,0 @@
-name: Sonar CI
-on:
-  push:
-    branches:
-    - master
-    - '[4-9]+.[0-9]+.x'
-    - sonar
-
-jobs:
-  build:
-
-    runs-on: ubuntu-latest
-    if: ${{ github.repository_owner == 'OpenAPITools' }}
-    steps:
-    - uses: actions/checkout@v4
-    - name: Set up JDK 11
-      uses: actions/setup-java@v4
-      with:
-        distribution: 'temurin'
-        java-version: 11
-    - name: Compile with Maven
-      run: ./mvnw -B -q clean install jacoco:report
-    - name: Jacoco Aggregate
-      run: ./mvnw jacoco:report-aggregate
-    - name: Publish to Sonar
-      run: ./mvnw -B -q -nsu sonar:sonar -Dsonar.projectKey=OpenAPITools_openapi-generator -Dsonar.organization=openapitools -Dsonar.host.url=https://sonarcloud.io -Dsonar.login=${{ secrets.SONAR_LOGIN }} -Dsonar.branch.name=${GITHUB_REF##*/}