Aggregation project stage doesn't accept string

[fraction01]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Mongoose version

8.10.1

Node.js version

20

MongoDB server version

4.4

Typescript version (if applicable)

5.7.3

Description

project stage doesn't accept string as in the doc:

// include a, include b, exclude _id
aggregate.project("a b -_id");

Typescript error:

Argument of type 'string' is not assignable to parameter of type '{ [field: string]: any; }'.ts(2345)

I think string | is missing in

mongoose/types/pipelinestage.d.ts

Lines 211 to 214 in 633ff8d

	export interface Project {
	/** [`$project` reference](https://www.mongodb.com/docs/manual/reference/operator/aggregation/project/) */
	$project: { [field: string]: AnyExpression | Expression | Project['$project'] }
	}

Steps to Reproduce

Pass a string argument to the project stage

Expected Behavior

Should not show a Typescript error