Narrowly detect only Unauthorized status codes.

Signed-off-by: Corey Larson <corey@earthly.dev>

util/resolver/authorizer.go

@@ -401,7 +401,7 @@ func (ah *authHandler) fetchToken(ctx context.Context, sm *session.Manager, g se
 
 func invalidAuthorization(c auth.Challenge, responses []*http.Response) error {
 	lastResponse := responses[len(responses)-1]
-	if lastResponse.StatusCode >= http.StatusBadRequest {
+	if lastResponse.StatusCode == http.StatusUnauthorized {
 		return errors.Wrapf(docker.ErrInvalidAuthorization, "authorization status: %v", lastResponse.StatusCode)
 	}