[Feature] Add retry places when GOPROXY is needed

[xytan0056]

What version of gazelle are you using?

2078a44

What version of rules_go are you using?

9794aacb240809111dfb9d587d40475b2819310e

What version of Bazel are you using?

3.0.0

There are multiple places where GOPROXY is used to fetch module information
https://github.com/bazelbuild/bazel-gazelle/blob/master/cmd/fetch_repo/module.go#L77
https://github.com/bazelbuild/bazel-gazelle/blob/master/language/go/modules.go#L150
https://github.com/bazelbuild/bazel-gazelle/blob/master/repo/remote.go#L419
In an event where GOPROXY is not stable enough to provide 100% availability (especially considering an organization can maintain its own proxy to serve internal modules), go_repository would fail on a single try of these commands and cause the entire build to fail. Can we add an option to retry in this scenario?
This could be done in go 28194, but likely won't happen soon.

[jayconrod]

I'd rather not add this to Gazelle or fetch_repo. golang/go#28194 would be the place to implement it, though I'm skeptical it should be there either. Retries add complication, and if they're done poorly, they can add load to an already overloaded system.

It's possible to workaround this already with a local GOPROXY service that does retries.