cmd/dist: skip moved GOROOT on Go's Windows builders when not sharding tests
cmd/dist: skip moved GOROOT on Go's Windows builders when not sharding tests

Change-Id: I0bcae339624e7d61037d9ea0885b7bd07491bbb6
Reviewed-on: https://go-review.googlesource.com/51430
Run-TryBot: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

Cofyc/go,CAFxX/go,vsekhar/elastic-go,josharian/go,golang/go,golang/go,golang/go,vsekhar/elastic-go,akutz/go,codestation/go,cloudflare/go,vsekhar/elastic-go,golang/go,golang/go,codestation/go,akutz/go,codestation/go,polyverse-security/go,nawawi/go,CAFxX/go,polyverse-security/go,vsekhar/elastic-go,nawawi/go,golang/go,akutz/go,josharian/go,codestation/go,polyverse-security/go,josharian/go,nawawi/go,CAFxX/go,codestation/go,codestation/go,polyverse-security/go,josharian/go,cloudflare/go,codestation/go,nawawi/go,nawawi/go,akutz/go,akutz/go,josharian/go,akutz/go,golang/go,CAFxX/go,CAFxX/go,Cofyc/go,cloudflare/go,Cofyc/go,Cofyc/go,golang/go,Cofyc/go,CAFxX/go,akutz/go,polyverse-security/go,josharian/go,cloudflare/go,CAFxX/go,vsekhar/elastic-go,vsekhar/elastic-go,akutz/go,vsekhar/elastic-go,cloudflare/go,polyverse-security/go,CAFxX/go,Cofyc/go,cloudflare/go,nawawi/go,codestation/go,cloudflare/go,josharian/go,Cofyc/go,christopher-henderson/Go,nawawi/go,polyverse-security/go,vsekhar/elastic-go,polyverse-security/go,josharian/go,Cofyc/go,nawawi/go,cloudflare/go