Add global migration to purge orphan kbslugs keys from maindb

[jotare]

Description

Remove orphan kbslugs from maindb using a global migration

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Describe how you tested this PR.

[shortcut-integration[bot]]

This pull request has been linked to Shortcut Story #9383: Fix /kbslugs deletion problem.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 83.90%. Comparing base (f6aa104) to head (b264480). Report is 31 commits behind head on main.

:exclamation: Current head b264480 differs from pull request most recent head 98a5fda. Consider uploading reports for the commit 98a5fda to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1963      +/-   ##
==========================================
- Coverage   83.91%   83.90%   -0.01%     
==========================================
  Files         326      326              
  Lines       17677    17675       -2     
==========================================
- Hits        14834    14831       -3     
- Misses       2843     2844       +1     

Flag	Coverage Δ
ingest	68.53% <ø> (-0.05%)	:arrow_down:
utils	81.68% <ø> (ø)

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