feat!: Remove Studio Maintenance link (attempt 2)

[kdmccormick]

Description

This reverts commit 48c49fe.

The original commit (a229c34) was merged prematurely, so it was reverted. However, now that we have properly DEPR'd the underlying feature, we can revert that revert.

Part of: openedx/edx-platform#36263

Screenshots

This removes the "Maintenance" link here:

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 73.28%. Comparing base (ef0ea13) to head (ade4776).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #642      +/-   ##
==========================================
- Coverage   73.33%   73.28%   -0.06%     
==========================================
  Files          55       55              
  Lines         510      509       -1     
  Branches      100      100              
==========================================
- Hits          374      373       -1     
  Misses        133      133              
  Partials        3        3              

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