Generate webui artifacts as part of build process

crates/librqbit/build.rs

@@ -2,6 +2,8 @@ use std::path::Path;
 use std::process::Command;
 
 fn main() {
+    #[cfg(feature = "webui")]
+    {
         let webui_dir = Path::new("webui");
         let webui_src_dir = webui_dir.join("src");
 
@@ -24,4 +26,5 @@ fn main() {
 
         // Optionally print the stdout output if you want to see the build logs
         println!("{}", String::from_utf8_lossy(&output.stdout));
+    }
 }