Is your feature request related to a problem? Please describe.
HTTP/3 is in the works and as a project it would be in our best interest to support it out of the gate. As of this moment the spec has not been finalized however many major websites are already rolling it out.

HTTP/3 uses UDP as its underlying protocol and allows for the unblocking of packets in the instance of failures. It is also more tightly coupled with TLS making for more secure connections.

• Create documentation section for HTTP/3 transport ([DOC] Document for HTTP/3 transport support (server side, experimental) documentation-website#11697)
• Support HTTP/3 transport by OpenSearch security plugin ([FEATURE] Support for HTTP/3 (server side) security#5884)
• Add Alt-Svc header support to advertise HTTP/3 availability ([FEATURE] Add Alt-Svc header support to advertise HTTP/3 availability #20433)

Describe the solution you'd like
We should begin working on an HTTP/3 implementation with netty.

Describe alternatives you've considered
If we don't support it no one would probably notice but being ahead of the curve gives us a lot of credibility.

Additional context
RFC 9114 - HTTP/3
Netty Sample HTTP/3 Implementation
https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Alt-Svc
[HTTP/3 in the Wild: Why It Beats HTTP/2 Where It Matters Most](https://thenewstack.io/http-3-in-the-wild-why-it-beats-http-2-where-it-matters-most/