use the same JUnit version for all JUnit components

Author: asolntsev

gradle/dependencies.gradle

@@ -1,6 +1,5 @@
 ext {
   junitVersion = '6.0.0'
-  junitPlatformVersion = '6.0.0'
 }
 
 dependencies {
@@ -9,8 +8,8 @@ dependencies {
   implementation group: 'org.assertj', name: 'assertj-core', version: '3.27.6'
   testImplementation "org.junit.jupiter:junit-jupiter-api:$junitVersion"
   testImplementation "org.junit.jupiter:junit-jupiter-engine:$junitVersion"
-  testImplementation "org.junit.platform:junit-platform-engine:$junitPlatformVersion"
-  testImplementation "org.junit.platform:junit-platform-launcher:$junitPlatformVersion"
+  testImplementation "org.junit.platform:junit-platform-engine:$junitVersion"
+  testImplementation "org.junit.platform:junit-platform-launcher:$junitVersion"
 }
 
 repositories {