[JS IR] Do not copy interface method if base class inherits it

^KT-58599 Fixed

compiler/testData/codegen/box/size/removeUnusedOverride.kt

@@ -0,0 +1,20 @@
+// TARGET_BACKEND: JS_IR
+// TARGET_BACKEND: WASM
+
+// WASM_DCE_EXPECTED_OUTPUT_SIZE: wasm 13_005
+
+interface I {
+    fun foo() = "OK"
+}
+
+abstract class A : I
+
+class B : A()
+
+class C : A() {
+    override fun foo(): String {
+        return "C::foo"
+    }
+}
+
+fun box() = B().foo()