refactor: OPTIC-1356: Remove Stale Feature Flag

[mcanu]

PR fulfills these requirements

• Commit message(s) and PR title follows the format [fix|feat|ci|chore|doc]: TICKET-ID: Short description of change made ex. fix: DEV-XXXX: Removed inconsistent code usage causing intermittent errors
• Tests for the changes have been added/updated (for bug fixes/features)
• Docs have been added/updated (for bug fixes/features)
• Best efforts were made to ensure docs/code are concise and coherent (checked for spelling/grammatical errors, commented out code, debug logs etc.)
• Self-reviewed and ran all changes on a local instance (for bug fixes/features)

Change has impacts in these area(s)

(check all that apply)

• Product design
• Backend (Database)
• Backend (API)
• Frontend

Describe the reason for change

Cleaning up stale feature flag fflag-feat-front-dev-2982-label-weights-settings, stale since July. Has LSE changes.

Does this PR introduce a breaking change?

(check only one)

• Yes, and covered entirely by feature flag(s)
• Yes, and covered partially by feature flag(s)
• No
• Not sure (briefly explain the situation below)

What level of testing was included in the change?

(check all that apply)

• e2e
• integration
• unit

Which logical domain(s) does this change affect?

(for bug fixes/features, be as precise as possible. ex. Authentication, Annotation History, Review Stream etc.)

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.77%. Comparing base (e4434bc) to head (9c545da).
Report is 3 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #6690   +/-   ##
========================================
  Coverage    76.77%   76.77%           
========================================
  Files          170      170           
  Lines        13883    13883           
========================================
+ Hits         10658    10659    +1     
+ Misses        3225     3224    -1     

Flag	Coverage Δ
pytests	76.77% <ø> (+<0.01%)	⬆️

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