test: mark test as flaky

Refs: #51862

Ran into this a few times myself this week and also
seems to be a top failer in the reliability reports

Signed-off-by: Michael Dawson <midawson@redhat.com>
PR-URL: #52671
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>

test/parallel/parallel.status

@@ -12,6 +12,9 @@ test-shadow-realm-gc-module: PASS, FLAKY
 # https://github.com/nodejs/node/issues/52274
 test-worker-arraybuffer-zerofill: PASS, FLAKY
 
+# https://github.com/nodejs/node/issues/51862
+test-fs-read-stream-concurrent-reads: PASS, FLAKY
+
 [$system==win32]
 
 # Windows on x86