[FIR JS] Fix a typo in the dynamic upper bound check

`FirDynamicTypeRef` is the unresolved version, and after resolution it
becomes `FirResolvedTypeRef` with `ConeDynamicType`.

compiler/testData/diagnostics/testsWithJsStdLib/dynamicTypes/supertypesAndBounds.fir.kt

@@ -1,5 +0,0 @@
-interface Tr : <!DYNAMIC_SUPERTYPE!>dynamic<!>
-
-fun <T: dynamic> foo() {}
-
-class C<T> where T : dynamic

compiler/testData/diagnostics/testsWithJsStdLib/dynamicTypes/supertypesAndBounds.kt

@@ -1,3 +1,5 @@
+// FIR_IDENTICAL
+
 interface Tr : <!DYNAMIC_SUPERTYPE!>dynamic<!>
 
 fun <T: <!DYNAMIC_UPPER_BOUND!>dynamic<!>> foo() {}