Ensure watch_object handles objects removed before init

[markdingram]

Stream produced by watch_object will include an item when the object isn't in any initial list

fixes #1576

Motivation

Solution

No tests! I see there are attempts already in this area underway, e.g. #1529

I would be happy to add tests if/when those tests land

[codecov]

Codecov Report

Attention: Patch coverage is 92.85714% with 1 line in your changes missing coverage. Please review.

Project coverage is 75.3%. Comparing base (63644d2) to head (b49ab8c).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
kube-runtime/src/watcher.rs	92.9%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #1577     +/-   ##
=======================================
+ Coverage   75.3%   75.3%   +0.1%     
=======================================
  Files         82      82             
  Lines       7323    7331      +8     
=======================================
+ Hits        5511    5519      +8     
  Misses      1812    1812             

Files with missing lines	Coverage Δ
kube-runtime/src/watcher.rs	44.2% <92.9%> (+2.1%)	⬆️

[clux]

Thanks for this. I think this makes sense. A couple of quick questions to make sure i understand properly.

[clux]

Comments are clear, thank you!