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

js/js.translator/testData/box/incremental/inlineModuleVariable.kt

@@ -1,4 +1,3 @@
-// IGNORE_FIR
 // NO_COMMON_FILES
 // EXPECTED_REACHABLE_NODES: 1282
 // MODULE: lib
@@ -18,4 +17,4 @@ val dummy get() = js("\$module\$lib")
 
 // FILE: main.kt
 
-fun box() = proxy()
+fun box() = proxy()