Revert an unnecessary change

Author: shuoweil

bigframes/operations/output_schemas.py

@@ -14,6 +14,8 @@
 
 import pyarrow as pa
 
+from bigframes import dtypes
+
 
 def parse_sql_type(sql: str) -> pa.DataType:
     """
@@ -43,6 +45,9 @@ def parse_sql_type(sql: str) -> pa.DataType:
     if sql.upper() == "BOOL":
         return pa.bool_()
 
+    if sql.upper() == "JSON":
+        return dtypes.JSON_ARROW_TYPE
+
     if sql.upper().startswith("ARRAY<") and sql.endswith(">"):
         inner_type = sql[len("ARRAY<") : -1]
         return pa.list_(parse_sql_type(inner_type))