feat(s2n-quic-dc): update MTU on dc path when MTU is updated #4888

Job	Run time
env	4s
s2n-quic-qns (debug)	2m 24s
s2n-quic-qns (release)	7m 5s
bench	18m 8s
perf (s2n-quic, s2n-quic)	1m 21s
attack (udp)	5m 26s
h3spec (s2n-tls)	14s
perf (s2n-quic-null, s2n-quic-null)	1m 0s
h3spec (rustls)	14s
interop (aioquic, s2n-quic)	15m 40s
interop (chrome, s2n-quic)	5m 18s
interop (go-x-net, s2n-quic)	11m 52s
interop (kwik, s2n-quic)	14m 10s
interop (lsquic, s2n-quic)	12m 57s
interop (msquic, s2n-quic)	16m 23s
interop (mvfst, s2n-quic)	11m 24s
interop (neqo, s2n-quic)	15m 45s
interop (ngtcp2, s2n-quic)	14m 5s
interop (picoquic, s2n-quic)	15m 40s
interop (quic-go, s2n-quic)	12m 44s
interop (quiche, s2n-quic)	20m 16s
interop (quinn, s2n-quic)	13m 31s
interop (s2n-quic, aioquic)	13m 18s
interop (s2n-quic, go-x-net)	11m 20s
interop (s2n-quic, haproxy)	11m 54s
interop (s2n-quic, kwik)	12m 40s
interop (s2n-quic, lsquic)	15m 13s
interop (s2n-quic, msquic)	11m 57s
interop (s2n-quic, mvfst)	9m 30s
interop (s2n-quic, neqo)	12m 43s
interop (s2n-quic, nginx)	10m 21s
interop (s2n-quic, ngtcp2)	13m 56s
interop (s2n-quic, picoquic)	12m 29s
interop (s2n-quic, quic-go)	11m 5s
interop (s2n-quic, quiche)	10m 58s
interop (s2n-quic, quinn)	12m 0s
interop (s2n-quic, s2n-quic)	12m 13s
interop (s2n-quic, s2n-quic-rustls)	16m 25s
interop (s2n-quic, xquic)	12m 5s
interop (s2n-quic-rustls, s2n-quic)	12m 47s
interop (xquic, s2n-quic)	15m 24s
perf-report	14s
interop-report	19s
	7h 34m 32s

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