Update Rust crate serde to 1.0.216 (#10)

Co-authored-by: oxide-renovate[bot] <146848827+oxide-renovate[bot]@users.noreply.github.com>

Author: oxide-renovate[bot]

Cargo.lock

@@ -13,7 +13,7 @@ matrix-sdk = { git = "https://github.com/matrix-org/matrix-rust-sdk.git", rev =
 regex = "1.11.1"
 ruma = { version = "0.10.1", features = ["events"] }
 ruma-common = "0.13.0"
-serde = { version = "1.0.215", features = ["derive"] }
+serde = { version = "1.0.216", features = ["derive"] }
 thiserror = "2.0.7"
 tokio = "1.42.0"
 tracing = "0.1.41"