Remove unused SonarQube configs and cache setup.

Cleaned up commented-out SonarQube configuration from `pom.xml` and removed redundant cache settings in `.gitlab-ci.yml`. This simplifies the build configuration and eliminates unused or unnecessary definitions.

.gitlab-ci.yml

@@ -43,10 +43,6 @@ on_commits:
     - echo "Running tests..."
     - cd ${GITLAB_CLONE_DIR}
     - mvn test
-  cache:
-    key: "${CI_JOB_NAME}"
-    paths:
-      - .maven-cache
   only:
     - /^feature.*$/
     - merge_request
@@ -59,12 +55,12 @@ sonarcloud_scan:
   image:
     name: sonarsource/sonar-scanner-cli:latest
     entrypoint: [ "" ]
-  cache:
-    key: "${CI_JOB_NAME}"
-    paths:
-      - .maven-cache
   script:
-    - sonar-scanner -Dsonar.projectKey=${SONAR_PROJECT_KEY} -Dsonar.organization=${SONAR_ORGANIZATION} -Dsonar.token=${SONAR_TOKEN} -Dsonar.exclusions=docs/** -Dsonar.java.binaries=target/classes
+    - sonar-scanner -Dsonar.projectKey=${SONAR_PROJECT_KEY} \
+      -Dsonar.organization=${SONAR_ORGANIZATION} \
+      -Dsonar.token=${SONAR_TOKEN} \
+      -Dsonar.exclusions=docs/** \
+      -Dsonar.java.binaries=target/classes
   only:
     - merge_requests
     - develop