Update Rust crate serde_yaml to 0.9.0

Author: renovate[bot]

grabber/Cargo.toml

@@ -11,5 +11,5 @@ chrono = { version = "0.4.19", features = ["unstable-locales"] }
 clap = { version = "3.0.0-beta.2", features = ["yaml", "wrap_help", "suggestions", "color"] }
 octocrab = "0.11.0"
 serde = "1.0.127"
-serde_yaml = "0.8.17"
+serde_yaml = "0.9.0"
 tokio = { version = "1.1.1", features = ["macros", "rt-multi-thread"] }