Make cli faster by reruning c_operator_type compilation dependent on modification of its source code

apis/c/operator/build.rs

@@ -2,10 +2,11 @@ use std::path::Path;
 
 fn main() {
     dora_operator_api_types::generate_headers(Path::new("operator_types.h"))
-        .expect("failed to create operator_api.h");
+        .expect("failed to create operator_types.h");
 
     // don't rebuild on changes (otherwise we rebuild on every run as we're
     // writing the `operator_types.h` file; cargo will still rerun this script
     // when the `dora_operator_api_types` crate changes)
-    println!("cargo:rerun-if-changed=");
+    println!("cargo:rerun-if-changed=../../rust/operator/types/src/lib.rs");
+    println!("cargo:rerun-if-changed=operator_api.h");
 }