Put LiveKitBridge Swift build directory in target (#2812)

Helps it get caught in a cargo clean. Joseph was having trouble building
a specific version of the app and deleting the Swift build dir for this
package resolved it. He had run cargo clean which would have handled
that if the Swift build dir was in `target` which this patch does


Release Notes:

- N/A

crates/live_kit_client/build.rs

@@ -58,11 +58,14 @@ fn build_bridge(swift_target: &SwiftTarget) {
         "cargo:rerun-if-changed={}/Package.resolved",
         SWIFT_PACKAGE_NAME
     );
+
     let swift_package_root = swift_package_root();
+    let swift_target_folder = swift_target_folder();
     if !Command::new("swift")
         .arg("build")
         .args(["--configuration", &env::var("PROFILE").unwrap()])
         .args(["--triple", &swift_target.target.triple])
+        .args(["--build-path".into(), swift_target_folder])
         .current_dir(&swift_package_root)
         .status()
         .unwrap()
@@ -128,6 +131,12 @@ fn swift_package_root() -> PathBuf {
     env::current_dir().unwrap().join(SWIFT_PACKAGE_NAME)
 }
 
+fn swift_target_folder() -> PathBuf {
+    env::current_dir()
+        .unwrap()
+        .join(format!("../../target/{SWIFT_PACKAGE_NAME}"))
+}
+
 fn copy_dir(source: &Path, destination: &Path) {
     assert!(
         Command::new("rm")
@@ -155,8 +164,7 @@ fn copy_dir(source: &Path, destination: &Path) {
 
 impl SwiftTarget {
     fn out_dir_path(&self) -> PathBuf {
-        swift_package_root()
-            .join(".build")
+        swift_target_folder()
             .join(&self.target.unversioned_triple)
             .join(env::var("PROFILE").unwrap())
     }