Schema annotations need only be a JVM library (cashapp#777)

We no longer use the schema types for anything but parsing and for simplicity we restrict them to the JVM. Thus, this library only needs to support the JVM.

redwood-schema/build.gradle

@@ -1,7 +1,2 @@
-apply plugin: 'org.jetbrains.kotlin.multiplatform'
+apply plugin: 'org.jetbrains.kotlin.jvm'
 apply plugin: 'com.vanniktech.maven.publish'
-apply plugin: 'org.jetbrains.dokka' // Must be applied here for publish plugin.
-
-kotlin {
-  apply from: "${rootDir}/addAllTargets.gradle"
-}