Align JUnit Jupiter platform launcher with engine

Gradle (8.12.x) seems to provide an older launcher which does not longer
work with the updated Jupiter Engine.

Drop unused Maven integration test dependencies (-> #372)

Author: ascheman

htmlSanityCheck-maven-plugin/build.gradle

@@ -16,10 +16,9 @@ dependencies {
     implementation("org.apache.maven.plugin-tools:maven-plugin-annotations:${mavenPluginToolsVersion}")
 
     testImplementation libs.junit.jupiter
+    testRuntimeOnly "org.junit.platform:junit-platform-launcher:1.12.2"
+    // Explicit Launcher Version to override Gradle default
     testImplementation 'org.assertj:assertj-core:3.27.3'
-
-    testImplementation 'com.soebes.itf.jupiter.extension:itf-assertj:0.13.1'
-    testImplementation 'com.soebes.itf.jupiter.extension:itf-jupiter-extension:0.13.1'
 }
 
 test {