cmd/go/internal/modfetch: retry rename for unzipped directories
cmd/go/internal/modfetch: retry rename for unzipped directories

No test because this is difficult to reproduce, and such a test would
always be flaky.

Updates #36568

Change-Id: I8170410a7729ecc6f90baf8005444d6b1241185e
Reviewed-on: https://go-review.googlesource.com/c/go/+/220978
Run-TryBot: Jay Conrod <f3fadaedc813344da5ec13b41e26596889cc5baa@google.com>
Reviewed-by: Bryan C. Mills <1c8aad60184261ccede67f5c63a0d2a3bf3c9ff4@google.com>
Reviewed-by: Michael Matloob <4562438b12c14e81a47550acde616ff328a909f8@golang.org>

akutz/go,golang/go,cloudflare/go,akutz/go,akutz/go,nawawi/go,golang/go,nawawi/go,cloudflare/go,akutz/go,CAFxX/go,nawawi/go,CAFxX/go,golang/go,golang/go,cloudflare/go,akutz/go,CAFxX/go,CAFxX/go,nawawi/go,golang/go,CAFxX/go,akutz/go,nawawi/go,cloudflare/go,golang/go,akutz/go,nawawi/go,cloudflare/go,CAFxX/go,cloudflare/go,CAFxX/go,cloudflare/go,nawawi/go,akutz/go,cloudflare/go,nawawi/go,golang/go,CAFxX/go,golang/go