perf: Build less when TOML is needed

Author: epage

Cargo.toml

@@ -119,12 +119,13 @@ json5 = ["json5_rs", "serde/derive"]
 convert-case = ["convert_case"]
 preserve_order = ["indexmap", "toml?/preserve_order", "serde_json?/preserve_order", "ron?/indexmap"]
 async = ["async-trait"]
+toml = ["dep:toml"]
 
 [dependencies]
 serde = "1.0"
 
 async-trait = { version = "0.1", optional = true }
-toml = { version = "0.8", optional = true }
+toml = { version = "0.8", optional = true, default-features = false, features = ["parse"] }
 serde_json = { version = "1.0", optional = true }
 yaml-rust2 = { version = "0.9", optional = true }
 rust-ini = { version = "0.21", optional = true }