[test] Mute failing irText tests

compiler/testData/ir/irText/classes/initBlock.kt

@@ -1,5 +1,7 @@
 // FIR_IDENTICAL
 // WITH_STDLIB
+// IGNORE_BACKEND_K2: JS_IR
+// IGNORE_BACKEND_K2: JS_IR_ES6
 
 class Test1 {
     init {
@@ -43,4 +45,4 @@ class Test5 {
             println("2")
         }
     }
-}
+}