Get rid of kotlinx-coroutines usage in scripting libs and plugins

the dependency on the coroutines library caused various problems like
KT-30778, or stdlib/runtime version conflicts.
The only function used was `runBlocking`, so this change replaces it
with the internal implementation based on the similar internal thing
from the stdlib.
#KT-30778 fixed

plugins/scripting/scripting-compiler-impl-embeddable/build.gradle.kts

@@ -10,7 +10,6 @@ dependencies {
     runtimeOnly(project(":kotlin-scripting-common"))
     runtimeOnly(project(":kotlin-scripting-jvm"))
     runtimeOnly(kotlinStdlib())
-    runtimeOnly(commonDep("org.jetbrains.kotlinx", "kotlinx-coroutines-core"))
 }
 
 publish()