Use DOCUMENTER_KEY in the tagbot workflow

[JamesWrigley]

Otherwise it will not trigger the docs build for the tag and the stable docs will be out of date.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.75%. Comparing base (5daab3f) to head (fdda51a).

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #75   +/-   ##
=======================================
  Coverage   88.75%   88.75%           
=======================================
  Files          13       13           
  Lines        2277     2277           
=======================================
  Hits         2021     2021           
  Misses        256      256           

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[JamesWrigley]

For the record, I manually built and pushed the docs for v1.3.2 so they should be up to date now.

[giordano]

You don't have to do that: https://documenter.juliadocs.org/stable/man/hosting/#Fixing-broken-release-deployments

[JamesWrigley]

Ah hah, good to know 👍