feat(server): add support for `idle_timeout`.

[finnbear]

See https://github.com/hyperium/hyper/pull/3743

Draft until #3743 is merged.

Testing

• [x] Tested in my app

# Cargo.toml

[patch.crates-io]
hyper = { git = "https://github.com/finnbear/hyper", branch = "idle_timeout" }
hyper-util = { git = "https://github.com/finnbear/hyper-util", branch = "idle_timeout" }