fix(deps): update rust crate convert_case to 0.9.0

Author: renovate[bot]

book-examples/Cargo.toml

@@ -21,7 +21,7 @@ virtual = []
 [dependencies]
 console_error_panic_hook.workspace = true
 console_log.workspace = true
-convert_case = "0.8.0"
+convert_case = "0.9.0"
 floating-ui-leptos.workspace = true
 leptos = { workspace = true, features = ["csr"] }
 leptos-node-ref.workspace = true