fix(NODE-6367): enable mixed use of iteration APIs

[W-A-James]

Description

What is changing?

Is there new documentation needed for these changes?

No

What is the motivation for this change?

Fixing mixed use of cursor.next and for await (const doc of cursor).

Release Highlight

Fixed mixed use of cursor.next() and cursor[Symbol.asyncIterator]

In 6.8.0, we inadvertently prevented the use of cursor.next() along with using for await syntax to iterate cursors. If your code made use of the following pattern and the call to cursor.next retrieved all your documents in the first batch, then the for-await loop would never be entered. This issue is now fixed.

const firstDoc = await cursor.next();

for await (const doc of cursor) {
    // process doc
    // ...
}

Double check the following

• Ran npm run check:lint script
• Self-review completed using the steps outlined here
• PR title follows the correct format: type(NODE-xxxx)[!]: description
  • Example: feat(NODE-1234)!: rewriting everything in coffeescript
• Changes are covered by tests
• New TODOs have a related JIRA ticket