refactor: remove once_cell dependency and use std::sync equivalents (#4185)

packages/fullstack/Cargo.toml

@@ -41,7 +41,6 @@ dioxus-mobile = { workspace = true, optional = true }
 
 tracing = { workspace = true }
 tracing-futures = { workspace = true, optional = true }
-once_cell = { workspace = true }
 tokio-util = { workspace = true, features = ["rt"], optional = true }
 async-trait = { workspace = true, optional = true }
 

packages/fullstack/src/lib.rs

@@ -4,8 +4,6 @@
 #![deny(missing_docs)]
 #![cfg_attr(docsrs, feature(doc_cfg))]
 
-pub use once_cell;
-
 #[cfg(all(feature = "web", feature = "document"))]
 mod web;