Use cargo workspace lints

cove-macro/src/lib.rs

@@ -1,14 +1,3 @@
-#![forbid(unsafe_code)]
-// Rustc lint groups
-#![warn(future_incompatible)]
-#![warn(rust_2018_idioms)]
-#![warn(unused)]
-// Rustc lints
-#![warn(noop_method_call)]
-#![warn(single_use_lifetimes)]
-// Clippy lints
-#![warn(clippy::use_self)]
-
 use syn::{parse_macro_input, DeriveInput};
 
 mod document;