libs/kaptan-mavlink: remove specification build hook

libs/kaptan-mavlink/build.rs

@@ -1,8 +1,6 @@
 use std::path::PathBuf;
 
 fn main() {
-    kaptan_spec::validate_package();
-
     let manifest_directory = PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
     let dialect = manifest_directory.join("definitions/kaptan.xml");
     let output_directory = std::env::var("OUT_DIR").unwrap();