Use Case

See https://mongodb.slack.com/archives/C72LB5RPV/p1729101189007139.

Shane pointed out recently that the logic for findOne sets a batch size of 1 that isn't needed:

const cursor = this.find(filter, options).limit(-1).batchSize(1);
    const res = await cursor.next();
    await cursor.close();
    return res;

This has no impact on the command built - because a `limit = -1` sets `singleBatch` to true on the find command with a `limit=1`. Other drivers don't set a batch size in this scenario, we could remove it for clarify and consistency with other drivers.

While we're here, we should omit `batchSize` as a FindOption, because we expect a single batch with only one document at most.

User Experience

n/a

Dependencies

n/a

Risks/Unknowns

n/a

Acceptance Criteria

Implementation Requirements

Omit batchSize as an option to findOne.
Don't set batchSize on the cursor before executing the find.

Testing Requirements

• unit test, spec test sync, etc

Documentation Requirements

• DOCSP ticket, API docs, etc

Follow Up Requirements

• additional tickets to file, required releases, etc
• if node behavior differs/will differ from other drivers, confirm with dbx devs what standard to aim for and what plan, if any, exists to reconcile the diverging behavior moving forward