Run gopls modernize on codebase (#34751)

Recent modernize fixes:
https://github.com/golang/tools/commits/master/gopls/internal/analysis/modernize

services/oauth2_provider/access_token.go

@@ -85,7 +85,7 @@ func GrantAdditionalScopes(grantScopes string) auth.AccessTokenScope {
 	}
 
 	var accessScopes []string // the scopes for access control, but not for general information
-	for _, scope := range strings.Split(grantScopes, " ") {
+	for scope := range strings.SplitSeq(grantScopes, " ") {
 		if scope != "" && !slices.Contains(generalScopesSupported, scope) {
 			accessScopes = append(accessScopes, scope)
 		}