Use consistent junit version

Author: testower

gbfs-validator-java-api/pom.xml

@@ -29,6 +29,7 @@
     <properties>
         <java.version>17</java.version>
         <openapi-generator-maven-plugin>6.0.0</openapi-generator-maven-plugin>
+        <junit.version>5.12.0</junit.version>
     </properties>
     <dependencies>
         <dependency>
@@ -119,7 +120,7 @@
                 <dependency>
                     <groupId>org.junit.jupiter</groupId>
                     <artifactId>junit-jupiter-api</artifactId>
-                    <version>5.9.2</version>
+                    <version>${junit.version}</version>
                     <scope>test</scope>
                 </dependency>
     </dependencies>