docs: fix a typo in MAINTAINING.md

[fishmandev]

Fix a typo

[jsjoeio]

Thank you so much!

[codecov]

Codecov Report

Merging #4711 (1b0d364) into main (ca15d4b) will not change coverage.
The diff coverage is n/a.

❗ Current head 1b0d364 differs from pull request most recent head 4568c4b. Consider uploading reports for the commit 4568c4b to get more accurate results

@@           Coverage Diff           @@
##             main    #4711   +/-   ##
=======================================
  Coverage   69.10%   69.10%           
=======================================
  Files          29       29           
  Lines        1638     1638           
  Branches      341      341           
=======================================
  Hits         1132     1132           
  Misses        430      430           
  Partials       76       76           

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