Hydrate populated fields not mark them as populated in the document

[yamaha252]

Prerequisites

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

Mongoose version

8.8.2

Node.js version

20.7.0

MongoDB server version

5.0.2

Typescript version (if applicable)

5.6.3

Description

On hydrating a document with populated fields (hydratedPopulatedDocs: true), they doesn't pass document.populated(...) check.

Steps to Reproduce

const userSchema = new Schema({
  name: String
});
const companySchema = new Schema({
  name: String,
  users: [{ ref: 'User', type: Schema.Types.ObjectId }]
});

db.model('UserTestHydrate', userSchema);
const Company = db.model('CompanyTestHydrate', companySchema);

const users = [{ _id: new mongoose.Types.ObjectId(), name: 'Val' }];
const company = { _id: new mongoose.Types.ObjectId(), name: 'Booster', users: [users[0]] };

const C = Company.hydrate(company, null, { hydratedPopulatedDocs: true });
assert(C.populated('users')); // fails

AssertionError [ERR_ASSERTION]: The expression evaluated to a falsy value:
assert(C.populated('users'))

Expected Behavior

Hydrating populated fields should write population info in the document to make populated method works.