cases: update for new error

The latest bugfix reverted this case to its old behavior (which is a
reasonable behavior to have).

test/cases/compile_errors/enum_field_value_references_nonexistent_circular.zig

@@ -9,8 +9,5 @@ export fn entry() void {
 const D = 1;
 
 // error
-// backend=stage2
-// target=native
 //
-// :2:13: error: enum 'tmp.Foo' has no member named 'B'
-// :1:17: note: enum declared here
+// :1:5: error: dependency loop detected