replace unmaintained yaml-rust with yaml-rust2

Cargo.toml

@@ -17,7 +17,7 @@ exclude = [
 serde = { version = "1.0.137", features = ["derive"] }
 json = { package = "serde_json", version = "1.0.81" }
 toml = { version = "0.5.9", optional = true }
-yaml = { package = "yaml-rust", version = "0.4.5", optional = true }
+yaml = { package = "yaml-rust2", version = "0.8.0", optional = true }
 
 [features]
 default = ["toml", "yaml"]