Move parking_lot/send_guard from send to userdata-wrappers feature.

Related to #553

Author: khvzak

Cargo.toml

@@ -38,12 +38,12 @@ luau-vector4 = ["luau", "ffi/luau-vector4"]
 vendored = ["ffi/vendored"]
 module = ["mlua_derive", "ffi/module"]
 async = ["dep:futures-util"]
-send = ["parking_lot/send_guard", "error-send"]
+send = ["error-send"]
 error-send = []
 serialize = ["dep:serde", "dep:erased-serde", "dep:serde-value", "bstr/serde"]
 macros = ["mlua_derive/macros"]
 anyhow = ["dep:anyhow", "error-send"]
-userdata-wrappers = []
+userdata-wrappers = ["parking_lot/send_guard"]
 
 [dependencies]
 mlua_derive = { version = "=0.11.0-beta.1", optional = true, path = "mlua_derive" }