feat: Support multiple top-level windows on Unix (#292)

Author: DataTriny

Cargo.lock

@@ -13,15 +13,16 @@ edition = "2021"
 [features]
 default = ["async-io"]
 async-io = ["zbus/async-io"]
-tokio = ["dep:once_cell", "dep:tokio", "zbus/tokio"]
+tokio = ["dep:tokio", "zbus/tokio"]
 
 [dependencies]
 accesskit = { version = "0.11.2", path = "../../common" }
 accesskit_consumer = { version = "0.15.2", path = "../../consumer" }
 async-channel = "1.8.0"
+async-once-cell = "0.5.3"
 atspi = { version = "0.10.1", default-features = false }
 futures-lite = "1.12.0"
-once_cell = { version = "1.17.1", optional = true }
+once_cell = "1.17.1"
 serde = "1.0"
 tokio = { version = "1.10.0", optional = true, features = ["rt", "net", "time"] }
 zbus = { version = "3.6", default-features = false }