Disable unexpected cfg lint for cfg(loom)

Author: robin-nitrokey

Cargo.toml

@@ -13,3 +13,6 @@ categories = ["development-tools", "embedded"]
 
 [target.'cfg(loom)'.dependencies]
 loom = "0.5"
+
+[lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = ["cfg(loom)"] }