fix localtime_to_timestamp tool throws 'no attribute localize error' when it executes without specifying a timezone parameter (#23517)

Author: goofy-z

api/core/tools/builtin_tool/providers/time/tools/localtime_to_timestamp.py

@@ -37,12 +37,12 @@ def _invoke(
     @staticmethod
     def localtime_to_timestamp(localtime: str, time_format: str, local_tz=None) -> int | None:
         try:
+            local_time = datetime.strptime(localtime, time_format)
             if local_tz is None:
-                local_tz = datetime.now().astimezone().tzinfo
-            if isinstance(local_tz, str):
+                localtime = local_time.astimezone()  # type: ignore
+            elif isinstance(local_tz, str):
                 local_tz = pytz.timezone(local_tz)
-            local_time = datetime.strptime(localtime, time_format)
-            localtime = local_tz.localize(local_time)  # type: ignore
+                localtime = local_tz.localize(local_time)  # type: ignore
             timestamp = int(localtime.timestamp())  # type: ignore
             return timestamp
         except Exception as e: