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

js/js.translator/testData/box/crossModuleRef/object.kt

@@ -1,4 +1,3 @@
-// IGNORE_FIR
 // EXPECTED_REACHABLE_NODES: 1289
 // MODULE: lib
 // FILE: lib.kt
@@ -34,4 +33,4 @@ fun box(): String {
     if (log != "before;O.init;after;") return "fail: wrong evaluation order: $log"
 
     return "OK"
-}
+}