fix(models): use is and is not for type comparisons

Author: wu-vincent

src/dwarf2cpp/models.py

@@ -191,7 +191,7 @@ def merge(self, other: Object) -> bool:
         if not isinstance(other, TypeDef):
             return False
 
-        if self.kind != other.kind or self.name != other.name or type(self.value) != type(other.value):
+        if self.kind != other.kind or self.name != other.name or type(self.value) is not type(other.value):
             return False
 
         if isinstance(self.value, str):