Skip IndexedDB cleanup on Safari 15 (#5717)

* Skip IndexedDB cleanup on Safari 15
This PR changes our IndexedDB shutdown to skip all remaining work items on Safari 15. It is believed that writing to IndexedDB during unload can trigger a bug on Safari that prevents IndexedDB from loading during the next page load.

* Create lovely-bobcats-punch.md

Author: cmditch

.changeset/lovely-bobcats-punch.md

@@ -0,0 +1,5 @@
+---
+"@firebase/firestore": patch
+---
+
+The SDK no longer accesses IndexedDB during a page unload event on Safari 15. This aims to reduce the occurrence of an IndexedDB bug in Safari (https://bugs.webkit.org/show_bug.cgi?id=226547).

packages/firestore/src/local/indexeddb_persistence.ts

@@ -962,10 +962,10 @@ export class IndexedDbPersistence implements Persistence {
         // to make sure it gets a chance to run.
         this.markClientZombied();
 
-        if (isSafari() && navigator.appVersion.match(`Version/14`)) {
-          // On Safari 14, we do not run any cleanup actions as it might trigger
-          // a bug that prevents Safari from re-opening IndexedDB during the
-          // next page load.
+        if (isSafari() && navigator.appVersion.match(/Version\/1[45]/)) {
+          // On Safari 14 and 15, we do not run any cleanup actions as it might
+          // trigger a bug that prevents Safari from re-opening IndexedDB during
+          // the next page load.
           // See https://bugs.webkit.org/show_bug.cgi?id=226547
           this.queue.enterRestrictedMode(/* purgeExistingTasks= */ true);
         }