fix: Task processor overload when handling high volume SDK traffic

[khvn26]

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Changes

After changes introduced in #5356 and #5330, we've been seeing noticeable task processor congestion. In this PR, we force request tracking to a threaded mode to avoid it.

How did you test this code?

Made sure the unit test suite passes.

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3 Skipped Deployments

Name	Status	Preview	Comments	Updated (UTC)
docs	⬜️ Ignored (Inspect)	Visit Preview		Apr 21, 2025 10:23am
flagsmith-frontend-preview	⬜️ Ignored (Inspect)	Visit Preview		Apr 21, 2025 10:23am
flagsmith-frontend-staging	⬜️ Ignored (Inspect)	Visit Preview		Apr 21, 2025 10:23am

[github-actions]

Docker builds report

Image	Build Status	Security report
ghcr.io/flagsmith/flagsmith-e2e:pr-5358	Finished ✅	Skipped
ghcr.io/flagsmith/flagsmith-api-test:pr-5358	Finished ✅	Skipped
ghcr.io/flagsmith/flagsmith-api:pr-5358	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith-frontend:pr-5358	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith-private-cloud:pr-5358	Finished ✅	Results ✅
ghcr.io/flagsmith/flagsmith:pr-5358	Finished ✅	Results ✅

[github-actions]

Uffizzi Preview deployment-62969 was deleted.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.61%. Comparing base (de92415) to head (dd44f87).
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5358   +/-   ##
=======================================
  Coverage   97.61%   97.61%           
=======================================
  Files        1237     1237           
  Lines       42971    42971           
=======================================
  Hits        41948    41948           
  Misses       1023     1023           

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