Do not use CodSpeedHQ/action on fork

[radarhere]

I've noticed that codspeed is failing in my fork - https://github.com/radarhere/Pillow/actions/runs/28502089873/job/84481570060

Uploading results
  CodSpeed Run Hash: "ac9229155c02b8c001a1368595350a49a27a52b738385214d2cddf9c336dacb4"
  Error: Failed to retrieve upload data: 401 Unauthorized
    -> Reason: Repository not found or the user does not have access to it.
  
  Check that the workflow is correctly authenticated. View more at https://codspeed.io/docs/integrations/ci/github-actions/configuration#authentication

There doesn't appear to be any way to instruct CodSpeedHQ/action not to try and upload the results, so this runs pytest with codspeed normally in a separate step on forks.

[codspeed-hq]

Merging this PR will not alter performance

✅ 345 untouched benchmarks
⏩ 2 skipped benchmarks¹

---

_{Comparing radarhere:benchmark (71f0071) with main (1518f6c)}

Footnotes

1. 2 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[hugovk]

I've enabled CodSpeed for my fork so it can upload.

Is disabling the workflow acceptable?

Or would you prefer to have it run (and not fail uploading)?

[radarhere]

Oh, ok, I presumed that it would only upload to Pillow's main repository.