Update _json.py

Author: will-larkin

pandas/io/json/_json.py

@@ -957,7 +957,7 @@ def _read_pyarrow(self) -> DataFrame:
         pa_table = pyarrow_json.read_json(self.data)
         df = arrow_table_to_pandas(pa_table, dtype_backend=self.dtype_backend)
 
-        if isinstance(dict, self.dtype):
+        if isinstance(self.dtype, dict):
             df = df.astype(self.dtype)
 
         return df