CI: add skip check avoid frequently creating PR

[Zeroto521]

• closes CI: add workflow to automatically update versioneer #319
• whatsnew entry

.github/workflows/versioneer.py would frequently create PR, I hate that.

[codecov]

Codecov Report

Merging #397 (9445901) into master (6c1a1ae) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #397   +/-   ##
=======================================
  Coverage   99.81%   99.81%           
=======================================
  Files          23       23           
  Lines         551      551           
  Branches       74       74           
=======================================
  Hits          550      550           
  Partials        1        1           

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