test: mark test/parallel/test-file-write-stream4 as flaky

PR-URL: #47423
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

Author: anonrig

test/parallel/parallel.status

@@ -23,6 +23,8 @@ test-child-process-stdio-reuse-readable-stdio: PASS, FLAKY
 [$system==linux]
 # https://github.com/nodejs/node/issues/39368
 test-domain-error-types: PASS,FLAKY
+# https://github.com/nodejs/node/issues/47420
+test-file-write-stream4: PASS,FLAKY
 
 [$system==macos]
 # https://github.com/nodejs/node/issues/42741