feat: Add logic to increment GroupTombstone hits asynchronously

[priscilawebdev]

Contributes to https://linear.app/getsentry/issue/TET-595/display-discarded-issue-count-and-timestamp-for-each-entry-in

[codecov]

Codecov Report

Attention: Patch coverage is 86.84211% with 5 lines in your changes missing coverage. Please review.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/sentry/event_manager.py	64.28%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #93685      +/-   ##
==========================================
+ Coverage   88.04%   88.08%   +0.04%     
==========================================
  Files       10358    10343      -15     
  Lines      598302   597697     -605     
  Branches    23239    23123     -116     
==========================================
- Hits       526761   526502     -259     
+ Misses      71073    70702     -371     
- Partials      468      493      +25     

[markstory]

You don't want to include the current count here. Instead only pass 1 here. The buffers system will generate F(column) + value when the buffered values are flushed to postgres.

[priscilawebdev]

yes just noticed that. that is why the test broke :)

[markstory]

You could combine all of these

with (
  mock.patch(...),
  self.feature(...)
):

which can help with the indentation levels.

[JoshFerge]

nit: prefer return early to minimize code arrowing, e.g. if not tombstone_id return

[github-actions]

This PR has a migration; here is the generated SQL for src/sentry/migrations/0930_add_hit_counter_columns_to_grouptombstone.py

for 0930_add_hit_counter_columns_to_grouptombstone in sentry

--
-- Add field last_seen to grouptombstone
--
ALTER TABLE "sentry_grouptombstone" ADD COLUMN "last_seen" timestamp with time zone DEFAULT '2025-06-23T09:37:22.724698+00:00'::timestamptz NULL;
ALTER TABLE "sentry_grouptombstone" ALTER COLUMN "last_seen" DROP DEFAULT;
--
-- Add field times_seen to grouptombstone
--
ALTER TABLE "sentry_grouptombstone" ADD COLUMN "times_seen" integer DEFAULT 0 NULL CHECK ("times_seen" >= 0);
ALTER TABLE "sentry_grouptombstone" ALTER COLUMN "times_seen" DROP DEFAULT;