[JS] Remove non-functional IGNORE_FIR directive in js box tests

js/js.translator/testData/box/jsQualifier/classes.kt

@@ -1,4 +1,3 @@
-// IGNORE_FIR
 // EXPECTED_REACHABLE_NODES: 1282
 // MODULE: lib
 // FILE: lib.kt
@@ -14,4 +13,4 @@ external class C {
 // MODULE: main(lib)
 // FILE: main.kt
 
-fun box() = C().o() + C.D().k()
+fun box() = C().o() + C.D().k()