chore: remove async-std deps from transport/quic

transports/quic/Cargo.toml

@@ -9,7 +9,6 @@ repository = "https://github.com/libp2p/rust-libp2p"
 license = "MIT"
 
 [dependencies]
-async-std = { version = "1.12.0", optional = true }
 futures = { workspace = true }
 futures-timer = "3.0.3"
 if-watch = { workspace = true }
@@ -27,15 +26,13 @@ ring = { workspace = true }
 
 [features]
 tokio = ["dep:tokio", "if-watch/tokio", "quinn/runtime-tokio"]
-async-std = ["dep:async-std", "if-watch/smol", "quinn/runtime-async-std"]
 
 # Passing arguments to the docsrs builder in order to properly document cfg's.
 # More information: https://docs.rs/about/builds#cross-compiling
 [package.metadata.docs.rs]
 all-features = true
 
 [dev-dependencies]
-async-std = { version = "1.12.0", features = ["attributes"] }
 libp2p-identity = { workspace = true, features = ["rand"] }
 libp2p-muxer-test-harness = { path = "../../muxers/test-harness" }
 libp2p-noise = { workspace = true }