feat(NODE-4767): Change abstract cursor return type (#3531)

Author: W-A-James

etc/notes/CHANGES_5.0.0.md

@@ -192,6 +192,11 @@ The new minimum supported Node.js version is now 14.20.1.
 The MongoClient option `promiseLibrary` along with the `Promise.set` export that allows specifying a custom promise library has been removed.
 This allows the driver to adopt async/await syntax which has [performance benefits](https://v8.dev/blog/fast-async) over manual promise construction.
 
+### Cursors now implement `AsyncGenerator` interface instead of `AsyncIterator`
+
+All cursor types have been changed to implement `AsyncGenerator` instead of `AsyncIterator`.
+This was done to make our typing more accurate.
+
 ### Cursor closes on exit of for await of loops
 
 Cursors will now automatically close when exiting a for await of loop on the cursor itself.

src/cursor/abstract_cursor.ts

@@ -288,7 +288,7 @@ export abstract class AbstractCursor<
     return bufferedDocs;
   }
 
-  async *[Symbol.asyncIterator](): AsyncIterator<TSchema, void> {
+  async *[Symbol.asyncIterator](): AsyncGenerator<TSchema, void, void> {
     if (this.closed) {
       return;
     }