add：registry ping timeout

[likhita-8091]

I see that registry ping does not have timeout handling. The makeFetcher function clearly has a ctx timeout handling. Why is it not set during ping? I currently set the easiest 3 second timeout.

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[likhita-8091]

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[codecov-io]

Codecov Report

Merging #808 into master will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #808   +/-   ##
=======================================
  Coverage   74.91%   74.91%           
=======================================
  Files         103      103           
  Lines        4309     4309           
=======================================
  Hits         3228     3228           
  Misses        605      605           
  Partials      476      476           

Impacted Files	Coverage Δ
pkg/v1/remote/transport/ping.go	100.00% <100.00%> (ø)

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[jonjohnsonjr]

I am okay with this being hardcoded to 2s for now, but that might be too low for people on really unreliable/slow internet. If we see that happening, I may make this configurable or just increase the timeout.

[jonjohnsonjr]

Thanks!

[likhita-8091]

Of course, 2s is indeed a bit short, because I just changed it briefly and temporarily. I hope you can change the specific configuration.