style(Echo): Move imports to top of build.rs and add allow attribute

Reorganize the build.rs script to follow Rust conventions by placing
the `use serde::Deserialize` import at the top of the file rather than
at the bottom. Add the `#![allow(non_snake_case)]` attribute to suppress
lints for potential non-snake_case naming patterns in future code, and
remove trailing whitespace.

Author: NikolaRHristov

build.rs

@@ -1,3 +1,7 @@
+#![allow(non_snake_case)]
+
+use serde::Deserialize;
+
 #[derive(Deserialize)]
 struct Toml {
 	package:Package,
@@ -19,5 +23,3 @@ fn main() {
 			.version
 	);
 }
-
-use serde::Deserialize;