fix(metrics): Move end_post_process metric call to earlier (#97848)

i think this was causing some minor inconsistencies with the data -
previously we were only tracking this for non-reprocessing but we are
tracking `start_post_process` for everything which means the delta
between those metrics was off.

Author: roggenkemper

src/sentry/tasks/post_process.py

@@ -657,6 +657,12 @@ def get_event_raise_exception() -> Event:
             )
             metric_tags["occurrence_type"] = group_event.group.issue_type.slug
 
+        track_event_since_received(
+            step="end_post_process",
+            event_data=event.data,
+            tags=metric_tags,
+        )
+
         if not is_reprocessed:
             received_at = event.data.get("received")
             saved_at = event.data.get("nodestore_insert")
@@ -680,12 +686,6 @@ def get_event_raise_exception() -> Event:
                     tags=metric_tags,
                 )
 
-                track_event_since_received(
-                    step="end_post_process",
-                    event_data=event.data,
-                    tags=metric_tags,
-                )
-
             else:
                 metrics.incr("events.missing_received", tags=metric_tags)