fix(example): unlisten to event on tab change in api example (#1436)

* unlisten to event on tab change in api example

* rewrite

Co-authored-by: Lucas Nogueira <lucas@tauri.studio>

examples/api/src/components/Communication.svelte

@@ -1,10 +1,19 @@
 <script>
   import { listen, emit } from "@tauri-apps/api/event";
   import { invoke } from "@tauri-apps/api/tauri";
+  import { onMount, onDestroy } from "svelte";
 
   export let onMessage;
+  let unlisten;
 
-  listen("rust-event", onMessage)
+  onMount(async () => {
+    unlisten = await listen("rust-event", onMessage)
+  })
+  onDestroy(() => {
+    if (unlisten) {
+      unlisten()
+    }
+  })
 
   function log() {
     invoke("log_operation", {