fix(build): Update build script and async function signature

ts_web/elements/sio-recorder.ts

@@ -104,7 +104,7 @@ export class SioRecorder extends DeesElement {
    * Starts an rrweb recording session that tracks the entire DOM,
    * including canvases and cross-origin iframes (if permissible).
    */
-  private async startRecording(): void {
+  private async startRecording(): Promise<void> {
     await this.domtoolsPromise;
     this.status = 'recording';
     this.events = [];