fix(deletions): Delete seer matched group hash metadata first

[armenzg]

When deleting a GroupHash row, all GroupHashMetadata rows pointing to it via seer_matched_grouphash need updating (see code):

sentry/src/sentry/models/grouphashmetadata.py

Lines 115 to 118 in 6982620

	# The `GroupHash` record representing the match Seer sent back as a match (if any)
	seer_matched_grouphash = FlexibleForeignKey(
	"sentry.GroupHash", related_name="seer_matchees", on_delete=models.SET_NULL, null=True
	)

Before #101720, we would only delete GroupHash rows and that would time out because we would stomp queries longer than 30 seconds. In #101720 we added the deletion of the GroupHashMetadata rows but we should have also added the updating.

The new code will have these three stages:

GroupHashMetadata.objects.filter(seer_matched_grouphash_id__in=hash_ids).update(seer_matched_grouphash=None)
GroupHashMetadata.objects.filter(grouphash_id__in=hash_ids).delete()
GroupHash.objects.filter(id__in=hash_ids).delete()

Fixes SENTRY-5ABJ.

For posterity, this is the top of the stack trace:

OperationalError
canceling statement due to user request

SQL: UPDATE "sentry_grouphashmetadata" SET "seer_matched_grouphash_id" = NULL WHERE "sentry_grouphashmetadata"."seer_matched_grouphash_id" IN (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/sentry/deletions/defaults/group.py	50.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##           master   #102612   +/-   ##
========================================
  Coverage   80.93%    80.93%           
========================================
  Files        8930      8930           
  Lines      391174    391191   +17     
  Branches    24858     24858           
========================================
+ Hits       316579    316629   +50     
+ Misses      74227     74194   -33     
  Partials      368       368           

[armenzg]

bugbot run

[armenzg]

bugbot run

[armenzg]

This is what we should have done from the beginning (#101720).

[yuvmen]

Nice :)