refactor(iroh): remove genawaiter usage from dht discovery #11837

Job	Run time
Android Build Only (aarch64-linux-android)	1m 4s
Android Build Only (armv7-linux-androideabi)	1m 4s
cargo deny	30s
Checking docs	1m 12s
Checking fmt	35s
check_semver	1m 8s
clippy_check	1m 15s
codespell	4s
Cross Build Only (x86_64-unknown-freebsd)	43s
Cross Test (i686-unknown-linux-gnu)	1m 22s
Minimal Supported Rust Version	1m 14s
Build wasm32	29s
CI Test Suite / Tests (ubuntu-latest, stable, all)	31s
CI Test Suite / Tests (windows-latest, stable, all, x86_64-pc-windows-msvc)	1m 10s
CI Test Suite / Tests (ubuntu-latest, stable, none)	1s
netsim-integration-tests / Netsim	1m 33s
CI Test Suite / Tests (windows-latest, stable, none, x86_64-pc-windows-msvc)	1s
CI Test Suite / Tests (ubuntu-latest, stable, default)	1s
CI Test Suite / Tests (windows-latest, stable, default, x86_64-pc-windows-msvc)	1m 10s
CI Test Suite / Tests (macOS-arm-latest, stable, all)	1m 22s
CI Test Suite / Tests (macOS-arm-latest, stable, none)	1s
CI Test Suite / Tests (macOS-arm-latest, stable, default)	1m 23s
	17m 53s

Provide feedback