[TabLayoutMediator] Don't try to detach an already detached TabLayout

Resolves #4547

GIT_ORIGIN_REV_ID=15c001c9fed1a70c0dc8adbe1477687c2b0a97ed
PiperOrigin-RevId: 757914288

Author: pubiqq

lib/java/com/google/android/material/tabs/TabLayoutMediator.java

@@ -147,6 +147,10 @@ public void attach() {
    * called before {@link #attach()} when a ViewPager2's adapter is changed.
    */
   public void detach() {
+    if (!attached) {
+      return;
+    }
+
     if (autoRefresh && adapter != null) {
       adapter.unregisterAdapterDataObserver(pagerAdapterObserver);
       pagerAdapterObserver = null;