fix: relax required stats fields (compute units, counts) to optional

[apify-service-account]

• Updates the auto-generated Pydantic models and TypedDicts based on the proposed OpenAPI specification changes.
• Based on apify-docs PR #2763.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.54%. Comparing base (dbd39d0) to head (3f4ca2b).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #947      +/-   ##
==========================================
- Coverage   94.56%   94.54%   -0.03%     
==========================================
  Files          48       48              
  Lines        5119     5116       -3     
==========================================
- Hits         4841     4837       -4     
- Misses        278      279       +1     

Flag	Coverage Δ
integration	92.84% <100.00%> (-0.13%)	⬇️
unit	83.42% <100.00%> (-0.01%)	⬇️

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[vdusek]

LGTM.

I just made the PR title more specific. The previous one ("Relax constraints on generated models based on updated specification") doesn't say much in the changelog (which constraints? which fields?), and we already have another PR with that exact title, so we'd get two identical changelog lines.

Please be more specific in these. And ask Claude if you can't come up with a good title 😄.