Inherit lints in a few more crates (#8958)

It's intended that all crates in this workspace have uniform lints, so
add inheritance to a few forgotten crates.

crates/slab/Cargo.toml

@@ -7,6 +7,7 @@ name = "wasmtime-slab"
 repository = "https://github.com/bytecodealliance/wasmtime"
 version.workspace = true
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[lints]
+workspace = true
 
 [dependencies]

crates/wiggle/macro/Cargo.toml

@@ -9,6 +9,9 @@ categories = ["wasm"]
 keywords = ["webassembly", "wasm"]
 repository = "https://github.com/bytecodealliance/wasmtime"
 
+[lints]
+workspace = true
+
 [lib]
 proc-macro = true
 test = false

crates/wiggle/macro/src/lib.rs

@@ -1,5 +1,3 @@
-extern crate proc_macro;
-
 use proc_macro::TokenStream;
 use quote::quote;
 use syn::parse_macro_input;