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

PR-URL: #50221
Refs: #49985
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Robert Nagy <[email protected]>

Author: anonrig

test/parallel/parallel.status

@@ -14,6 +14,8 @@ test-fs-rmdir-recursive: PASS, FLAKY
 # https://github.com./nodejs/node/issues/48300
 test-child-process-pipe-dataflow: PASS, FLAKY
 test-child-process-stdio-reuse-readable-stdio: PASS, FLAKY
+# https://github.com./nodejs/node/issues/49985
+test-runner-watch-mode: PASS, FLAKY
 
 # Windows on ARM
 [$system==win32 && $arch==arm64]