fix(ios): propagate error from BootedUDID instead of silently swallowing

internal/testrun/driver.go

@@ -41,7 +41,11 @@ func buildDriver(ctx context.Context, options Options, stdout io.Writer) (driver
 		"--platform", options.Platform,
 	}
 	if options.Platform == "ios" {
-		if udid := ios.BootedUDID(ctx); udid != "" {
+		udid, err := ios.BootedUDID(ctx)
+		if err != nil {
+			return nil, nil, fmt.Errorf("find booted simulator: %w", err)
+		}
+		if udid != "" {
 			sidecarArgs = append(sidecarArgs, "--udid", udid)
 		}
 	}