Include blob existence checks in retries

[jonjohnsonjr]

Currently we just fail outright if the registry returns a 500 during a
blob HEAD because it's not included in the retry logic. This is not
ideal, especially in cases where an upload actually succeeded but we
never got a response from the server so we're re-uploading a blob for no
reason.

[codecov-commenter]

Codecov Report

Merging #1307 (aa088a9) into main (86e1c81) will increase coverage by 0.05%.
The diff coverage is 84.21%.

@@            Coverage Diff             @@
##             main    #1307      +/-   ##
==========================================
+ Coverage   74.01%   74.07%   +0.05%     
==========================================
  Files         112      112              
  Lines        8386     8386              
==========================================
+ Hits         6207     6212       +5     
+ Misses       1575     1570       -5     
  Partials      604      604              

Impacted Files	Coverage Δ
pkg/v1/remote/write.go	64.82% <84.21%> (ø)
pkg/v1/remote/options.go	74.03% <0.00%> (+4.80%)	⬆️

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