[K/N]: Do not require JDK11 for :native:native.tests

This commit provides a small fix in the code of a native test runner so that JDK11 is not required and removes the JDK11 target for the atomicfu-compiler-plugin.

Fixes KT-61293

Merge-request: KT-MR-11757
Merged-by: Maria Sokolova <maria.sokolova@jetbrains.com>

native/native.tests/build.gradle.kts

@@ -3,8 +3,6 @@ plugins {
     id("jps-compatible")
 }
 
-project.configureJvmToolchain(JdkMajorVersion.JDK_11_0)
-
 dependencies {
     testImplementation(kotlinStdlib())
     testImplementation(commonDependency("org.jetbrains.kotlin:kotlin-reflect")) { isTransitive = false }