Update Rust crate samael to 0.0.19 (#8344)

Author: oxide-renovate[bot]

Cargo.lock

@@ -644,7 +644,7 @@ rustfmt-wrapper = "0.2"
 rustls = "0.22.2"
 rustls-pemfile = "2.2.0"
 rustyline = "14.0.0"
-samael = { version = "0.0.18", features = ["xmlsec"] }
+samael = { version = "0.0.19", features = ["xmlsec"] }
 schemars = "0.8.22"
 scopeguard = "1.2.0"
 secrecy = "0.10.0"