Update dependency org.openapitools:openapi-generator-maven-plugin to v7

Author: renovate[bot]

frontend/pom.xml

@@ -26,7 +26,7 @@
         <maven.compiler.target>${java.version}</maven.compiler.target>
         <exec.maven.plugin>3.5.0</exec.maven.plugin>
         <maven.clean.plugin>3.4.1</maven.clean.plugin>
-        <openapi-generator-version>6.6.0</openapi-generator-version>
+        <openapi-generator-version>7.13.0</openapi-generator-version>
         <sonar.sources>src</sonar.sources>
         <sonar.coverage.exclusions>src</sonar.coverage.exclusions>
     </properties>