Fix unimplemented error when loading bundles (#7058)

* Fix unimplemented error

* Create soft-nails-give.md

Author: wu-hui

.changeset/soft-nails-give.md

@@ -0,0 +1,5 @@
+---
+"@firebase/firestore": patch
+---
+
+Fix unimplemented error when loading bundles

packages/firestore/src/util/byte_stream.ts

@@ -59,7 +59,7 @@ export function toByteStreamReaderHelper(
     },
     async cancel(): Promise<void> {},
     releaseLock() {},
-    closed: Promise.reject('unimplemented')
+    closed: Promise.resolve()
   };
   return reader;
 }