Add link_cplusplus crate in desperate attempt to fix CI

Author: crumblingstatue

Cargo.toml

@@ -33,6 +33,7 @@ serde = ["dep:serde"]
 ci-headless = []
 
 [dependencies]
+link-cplusplus = "1.0.9"
 num-traits = "0.2.15"
 
 [dependencies.serde]

src/lib.rs

@@ -16,6 +16,8 @@
     clippy::unwrap_used
 )]
 
+extern crate link_cplusplus;
+
 #[macro_use]
 mod ffi;