Don't try cross-origin mounting against dockerhub

[jonjohnsonjr]

Fixes #1741

[codecov-commenter]

Codecov Report

Merging #1743 (d369248) into main (2472cbb) will increase coverage by 0.03%.
The diff coverage is 33.33%.

❗ Current head d369248 differs from pull request most recent head c5e2c4f. Consider uploading reports for the commit c5e2c4f to get more accurate results

@@            Coverage Diff             @@
##             main    #1743      +/-   ##
==========================================
+ Coverage   71.95%   71.99%   +0.03%     
==========================================
  Files         122      122              
  Lines        9820     9826       +6     
==========================================
+ Hits         7066     7074       +8     
+ Misses       2074     2073       -1     
+ Partials      680      679       -1     

Impacted Files	Coverage Δ
pkg/v1/remote/write.go	63.57% <33.33%> (+0.89%)	⬆️