fix(Toast): may lose forbid click when has multiple toasts (#5398)

src/toast/lock-click.ts

@@ -0,0 +1,17 @@
+let lockCount = 0;
+
+export function lockClick(lock: boolean) {
+  if (lock) {
+    if (!lockCount) {
+      document.body.classList.add('van-toast--unclickable');
+    }
+
+    lockCount++;
+  } else {
+    lockCount--;
+
+    if (!lockCount) {
+      document.body.classList.remove('van-toast--unclickable');
+    }
+  }
+}