Update Rust crate fantoccini to 0.21.0

Cargo.toml

@@ -6,7 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-fantoccini = "0.19.3"
+fantoccini = "0.21.0"
 penguin-config = "0.1.1"
 serde = "1.0.200"
 tokio = { version = "1", features = ["full"] }