Fix doc build

[SpacemanPaul]

Reason for this pull request

API and click documentation is not rendering in the 1.9 docs build.

Proposed changes

• Updated documentation requirements.txt. Had to do by hand as pyproj seems to be breaking pip-compile somehow.

• Tests added / passed

• Fully documented, including docs/about/whats_new.rst for all changes

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📚 Documentation preview 📚: https://datacube-core--1668.org.readthedocs.build/en/1668/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.54%. Comparing base (22dc077) to head (001ff62).
Report is 1 commits behind head on develop-1.9.

Additional details and impacted files

@@             Coverage Diff              @@
##           develop-1.9    #1668   +/-   ##
============================================
  Coverage        85.54%   85.54%           
============================================
  Files              143      143           
  Lines            15422    15422           
============================================
  Hits             13193    13193           
  Misses            2229     2229           

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[caitlinadams]

Thanks for fixing this, much appreciated!