Await destroyRawConnection in Postgres cancelQuery

lib/dialects/postgres/index.js

@@ -237,18 +237,12 @@ class Client_PG extends Client {
   }
 
   async cancelQuery(connectionToKill) {
-    // Error out if we can't acquire connection in time.
-    // Purposely not putting timeout on `pg_cancel_backend` execution because erroring
-    // early there would release the `connectionToKill` back to the pool with
-    // a `KILL QUERY` command yet to finish.
     const conn = await this.acquireRawConnection();
 
     try {
       return await this._wrappedCancelQueryCall(conn, connectionToKill);
     } finally {
-      // NOT returning this promise because we want to release the connection
-      // in a non-blocking fashion
-      this.destroyRawConnection(conn);
+      await this.destroyRawConnection(conn);
     }
   }
   _wrappedCancelQueryCall(conn, connectionToKill) {