refactor: convert watch tests to async functions

[dnalborczyk]

This PR contains:

• bugfix
• feature
• refactor
• documentation
• other

Are tests included?

• yes (bugfixes and features will not be merged without tests)
• no

Breaking Changes?

• yes (breaking changes will not be merged unless absolutely necessary)
• no

List any relevant issue numbers:

Description

[codecov]

Codecov Report

Merging #4385 (0f87d47) into master (e14cb51) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #4385   +/-   ##
=======================================
  Coverage   98.72%   98.72%           
=======================================
  Files         204      204           
  Lines        7315     7315           
  Branches     2082     2082           
=======================================
  Hits         7222     7222           
  Misses         34       34           
  Partials       59       59           

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[lukastaegert]

Nice one! I always thought this should be converted but never found the energy because there were so many tests.