[build] Fix weird dependencies management

kotlin-gradle-plugin-integration-tests on runtime uses relocated
compiler jars. A special handling is required to support this.

Looks like 'kotlin-gradle-plugin-test-utils' was meant to help
here somehow, but was accidentally broken at some point. It went
unnoticed because not much classes from transitive dependencies
of 'kotlin-gradle-plugin-test-utils' were used.

The change in this commit still leaves a few questions about this
configuration, but at leats it makes it possible to use compiler
classes (e.g. KotlinTestUtils)

libraries/tools/kotlin-gradle-plugin-integration-tests/build.gradle.kts

@@ -78,7 +78,7 @@ dependencies {
     // testCompileOnly dependency on non-shaded artifacts is needed for IDE support
     // testRuntimeOnly on shaded artifact is needed for running tests with shaded compiler
     testCompileOnly(project(":kotlin-gradle-plugin-test-utils-embeddable"))
-    testRuntimeOnly(project(":kotlin-gradle-plugin-test-utils-embeddable"))
+    testRuntimeOnly(project(":kotlin-gradle-plugin-test-utils-embeddable")) { isTransitive = false }
 
     testImplementation(project(path = ":examples:annotation-processor-example"))
     testImplementation(kotlinStdlib("jdk8"))

libraries/tools/kotlin-gradle-plugin-test-utils-embeddable/build.gradle.kts

@@ -21,6 +21,8 @@ dependencies {
         api(projectTests(projectName)) { isTransitive = false }
         embedded(projectTests(projectName)) { isTransitive = false }
     }
+
+    embedded(intellijJavaRt())
 }
 
 runtimeJar(rewriteDefaultJarDepsToShadedCompiler())