remove nickelliot/zli82016 from vacation reviewers (GoogleCloudPlatform#10080)

* Update membership.go

* Update membership.go

Author: NickElliot

.ci/magician/github/membership.go

@@ -46,10 +46,7 @@ var (
 	trustedContributors = []string{}
 
 	// This is for reviewers who are "on vacation": will not receive new review assignments but will still receive re-requests for assigned PRs.
-	onVacationReviewers = []string{
-		"zli82016",
-		"NickElliot",
-	}
+	onVacationReviewers = []string{}
 )
 
 type UserType int64