ref(seer grouping): Add platform to did_call_seer metric

[lobsterkatie]

This adds the event's platform as a tag on the did_call_seer metric. In order to streamline things a bit, it also adds a new helper, record_did_call_seer_metric, to make the actual datadog call. (This saves a lot of repetition of sample rate, tags, etc.)

Other than the new tag, the only behavior change is that we've been (in theory) also recording did_call_seer during backfill, in cases where the killswitch is enabled. This is a mistake, though a harmless one as we haven't actually had to engage the killswitches in the last few months, so all our current DD data should be legit. Regardless, this fixes that, and only calls the new helper when we have an event (which we only do during ingest, not backfill).

Note: Leaving this in draft because it won't typecheck until some other PRs have gone through, and in order to wait for new did_call_seer calls to be merged, at which point I'll rebase and include them.

[codecov]

Codecov Report

Attention: Patch coverage is 78.57143% with 3 lines in your changes missing coverage. Please review.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/sentry/seer/similarity/utils.py	62.50%	0 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #80965      +/-   ##
==========================================
- Coverage   78.48%   78.47%   -0.01%     
==========================================
  Files        7210     7208       -2     
  Lines      319545   319520      -25     
  Branches    43966    43966              
==========================================
- Hits       250799   250753      -46     
- Misses      62360    62372      +12     
- Partials     6386     6395       +9     

[jangjodi]

since event.platform can be None, should we make it unknown if it's None?

[getsantry]

This pull request has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you add the label WIP, I will leave it alone unless WIP is removed ... forever!

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"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀

[getsantry]

This issue has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you remove the label Waiting for: Community, I will leave it alone ... forever!

---

"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀