RJS-2809: Realm Web: Fix async iterator returned from watch (#6688)

* Fixed asyncIteratorFromResponseBody to apply our polyfill unconditionally

* Adding a note to the changelog

packages/realm-web/CHANGELOG.md

@@ -12,6 +12,7 @@
 ### Fixed
 * Fixed an endless loop of requests that would happen if linking credentials failed due to an authentication failure. ([#6588](https://github.com/realm/realm-js/pull/6588), since v0.6.0)
 * Logging in with `Credentials.anonymous()` credentials will now reuse any existing anonymous user which is already authenticated with the app. This aligns with the behaviour of the `realm` package and will result in less users being created. Use `Credentials.anonymous(false)` to disable this behaviour and achieve the old behaviour of creating new anonymous users on every login. ([#6592](https://github.com/realm/realm-js/pull/6592))
+* Fixed crash in Chrome from calling `stream.return()` on a watch stream. (PR [#6688](https://github.com/realm/realm-js/pull/6688))
 
 ### Internal
 * The base URL used to communicate with the Atlas App Services was changed from "https://realm.mongodb.com" to "https://services.cloud.mongodb.com". ([#6591](https://github.com/realm/realm-js/pull/6591))

packages/realm-web/src/Fetcher.ts

@@ -39,8 +39,6 @@ type SimpleObject = Record<string, unknown>;
 function asyncIteratorFromResponseBody({ body }: Response): AsyncIterable<Uint8Array> {
   if (typeof body !== "object" || body === null) {
     throw new Error("Expected a non-null object");
-  } else if (Symbol.asyncIterator in body) {
-    return body as AsyncIterable<Uint8Array>;
   } else if ("getReader" in body) {
     return {
       [Symbol.asyncIterator]() {