test: mark test-runner-watch-mode as flaky

PR-URL: #49627
Refs: #49605
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: LiviaMedeiros <livia@cirno.name>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>

Author: joyeecheung

test/parallel/parallel.status

@@ -24,6 +24,10 @@ test-domain-error-types: PASS,FLAKY
 # https://github.com/nodejs/node/issues/47420
 test-file-write-stream4: PASS,FLAKY
 
+[$system==linux || $system==win32]
+# https://github.com/nodejs/node/issues/49605
+test-runner-watch-mode: PASS,FLAKY
+
 [$system==macos]
 # https://github.com/nodejs/node/issues/42741
 test-http-server-headers-timeout-keepalive: PASS,FLAKY