Support graphviz version 0.16

[rwedge]

Fixes #1617

New build of the conda version of graphviz 0.16 works with windows, should fix the test errors.

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

Merging #1657 (2886b7b) into main (ce43af3) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1657   +/-   ##
=======================================
  Coverage   100.0%   100.0%           
=======================================
  Files         240      240           
  Lines       18476    18476           
=======================================
  Hits        18468    18468           
  Misses          8        8           

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[dsherry]

@rwedge thank you for following up on this! 👏

[dsherry]

@rwedge in order to get check_dependencies_updated_linux green you'll have to update the graphviz version in evalml/tests/dependency_update_check/latest_dependency_versions.txt to 0.16.