ci: temporary disable very flaky test

Disable "migrate_reuseport/IPv4 TCP_NEW_SYN_RECV reqsk_timer_handler"
test that recently became very flaky, causing a lot of CI churn.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

ci/vmtest/configs/DENYLIST

@@ -9,4 +9,5 @@ test_ima	# All of CI is broken on it following 6.3-rc1 merge
 lwt_reroute      # crashes kernel after netnext merge from 2ab1efad60ad "net/sched: cls_api: complement tcf_tfilter_dump_policy"
 tc_links_ingress # started failing after net-next merge from 2ab1efad60ad "net/sched: cls_api: complement tcf_tfilter_dump_policy"
 xdp_bonding/xdp_bonding_features     # started failing after net merge from 359e54a93ab4 "l2tp: pass correct message length to ip6_append_data"
-tc_redirect/tc_redirect_dtime # uapi breakage after net-next commit 885c36e59f46 ("net: Re-use and set mono_delivery_time bit for userspace tstamp packets")
+tc_redirect/tc_redirect_dtime # uapi breakage after net-next commit 885c36e59f46 ("net: Re-use and set mono_delivery_time bit for userspace tstamp packets")
+migrate_reuseport/IPv4 TCP_NEW_SYN_RECV reqsk_timer_handler # flaky, under investigation