Slightly refactor module dependencies of backend.js/serialization.js

The comment in serialization.js/build.gradle.kts is not needed because
such dependency cannot be introduced accidentally, since Gradle does not
support cycles in module dependencies.

compiler/ir/backend.js/build.gradle.kts

@@ -8,7 +8,6 @@ dependencies {
     compile(project(":compiler:frontend"))
     compile(project(":compiler:backend-common"))
     compile(project(":compiler:ir.tree"))
-    compile(project(":compiler:ir.psi2ir"))
     compile(project(":compiler:ir.backend.common"))
     compile(project(":compiler:ir.serialization.common"))
     compile(project(":compiler:ir.serialization.js"))

compiler/ir/serialization.js/build.gradle.kts

@@ -3,11 +3,10 @@ plugins {
     id("jps-compatible")
 }
 
-// Please make sure this module doesn't depend on `backend.js` (neither directly, nor transitively)
 dependencies {
-    compile(project(":compiler:ir.psi2ir"))
-    compile(project(":compiler:ir.serialization.common"))
-    compile(project(":js:js.frontend"))
+    api(project(":compiler:ir.psi2ir"))
+    api(project(":compiler:ir.serialization.common"))
+    api(project(":js:js.frontend"))
     implementation(project(":compiler:ir.backend.common"))
 
     compileOnly(intellijCoreDep()) { includeJars("intellij-core") }