ref: reuse type definition for Job from event_manager (#72706)

split out from my attempt to make Job a TypedDict

<!-- Describe your PR here. -->

src/sentry/grouping/ingest/hashing.py

@@ -2,8 +2,8 @@
 
 import copy
 import logging
-from collections.abc import MutableMapping, Sequence
-from typing import TYPE_CHECKING, Any
+from collections.abc import Sequence
+from typing import TYPE_CHECKING
 
 import sentry_sdk
 
@@ -35,12 +35,11 @@
 from sentry.utils.tag_normalization import normalized_sdk_tag_from_event
 
 if TYPE_CHECKING:
+    from sentry.event_manager import Job
     from sentry.eventstore.models import Event
 
 logger = logging.getLogger("sentry.events.grouping")
 
-Job = MutableMapping[str, Any]
-
 
 def _calculate_event_grouping(
     project: Project, event: Event, grouping_config: GroupingConfig