mock: Switch out xml-builder with quick-xml

Author: ColinKinloch

open-build-service-mock/Cargo.toml

@@ -16,6 +16,5 @@ rand = "0.8.5"
 serde = "1.0.125"
 strum = "0.23"
 strum_macros = "0.23"
-xml-builder = "=0.5.3"
 wiremock = "0.6.2"
 base64ct = { version = "1.6.0", features = ["std"] }