Update quinn-proto dependency from 0.11.6 to 0.11.8

Summary:
This fixes a panic that could cause a DoS vulnerability.

https://rustsec.org/advisories/RUSTSEC-2024-0373.html
GHSA-vr26-jcq5-fjj8
https://github.com/facebookincubator/reindeer/security/dependabot/16

quinn-proto 0.11.7 changelog: https://github.com/quinn-rs/quinn/releases/tag/quinn-proto-0.11.7
quinn-proto 0.11.8 changelog: https://github.com/quinn-rs/quinn/releases/tag/quinn-proto-0.11.8

Reviewed By: dtolnay

Differential Revision: D67530525

fbshipit-source-id: 59e3600b9e826471d97ee768bfb20b8122db12a0