fix every clippy warning possible, remove io_uring as default feature

this project's codebase is so horrendous, im shocked that no one has ran
clippy at all. it had ~200 total lint warnings, some with performance
issues and unsoundness, and the rest just very ugly codebase. i have sat
down and fixed as many of these as possible and i am exhausted.
i haven't fixed some extremely complex ones, but i brought it down from
~200 to ~30.

i have also removed io_uring as a default feature due to it falling
under the same category as linux eBPF: major kernel attack surface for
minimal performance gains. this also makes it impossible to cross-compile
from macOS to Linux because io_uring does not exist in Darwin land.
there are far better ways to achieve better performance than io_uring on
the codebase level.

Signed-off-by: strawberry <june@girlboss.ceo>

src/service/globals/mod.rs

@@ -164,7 +164,7 @@ impl Service {
             .dns_resolver(Arc::new(Resolver::new(Box::new(move |domain| {
                 let read_guard = name_override.read().unwrap();
                 let (override_name, port) = read_guard.get(domain)?;
-                let first_name = override_name.get(0)?;
+                let first_name = override_name.first()?;
                 Some(SocketAddr::new(*first_name, *port))
             }))))
             .build()?;