[PM-3483] Remove migrateKeyForNeverLockIfNeeded Logic

[justindbaur]

Type of change

- [x] Bug fix
- [ ] New feature development
- [x] Tech debt (refactoring, code cleanup, dependency upgrades, etc)
- [ ] Build/deploy pipeline (DevOps)
- [ ] Other

Objective

This helps fix a bug in MV3 where you could force stop the service worker from chrome://serviceworker-internals and then when the service worker restarted we would run VaultTimeoutService.init and in doing that we'd also run migrateKeyForNeverLockIfNeeded. Since the service worker restarting doesn't mean we lose our memory storage data, my user will still have a master key in memory. This tricked CryptoService.isLegacyUser into thinking that I was a legacy user and that I should be logged out. But this user isn't a legacy user and they don't use never lock. This meant that you could reopen your popup and you would be logged out when you would have expected to be logged in still.

Likely, there is logic wrong in these checks, since it would falsely report me as legacy when I was not, but this is also logic we had marked for deletion 6 months ago.

After deleting this code I can stop the service worker and open the popup back open still logged in.

Before you submit

• Please add unit tests where it makes sense to do so (encouraged but not required)
• If this change requires a documentation update - notify the documentation team
• If this change has particular deployment requirements - notify the DevOps team
• Ensure that all UI additions follow WCAG AA requirements

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 27.73%. Comparing base (b45c309) to head (8f7beff).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #8953   +/-   ##
=======================================
  Coverage   27.72%   27.73%           
=======================================
  Files        2407     2407           
  Lines       69745    69716   -29     
  Branches    12978    12971    -7     
=======================================
- Hits        19337    19335    -2     
+ Misses      48906    48879   -27     
  Partials     1502     1502           

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