[BUG] Inconsistent before_event trigger behavior

[paulpage]

Describe the bug
I have a before_event annotation to update a field on a document every time it is updated. The behavior the event handling is inconsistent based on what update method I use. I have a full reproduction that shows updating 4 documents in 4 different ways, with differing results:

1. find_one(...).update(...) - Not triggered, tag field NOT set in db
2. find_one(...); result.update(...) - Triggered ONCE, tag field NOT set in db
3. find_one(...); result.set(...) - Triggered ONCE, tag field NOT set in db
4. find_one(...); result.field = val; result.save() - Triggered TWICE; tag field SET in db

To Reproduce

import asyncio

from beanie import Document, Replace, Save, SaveChanges, Update, before_event
from beanie import init_beanie
from motor.motor_asyncio import AsyncIOMotorClient
from beanie.odm.operators.update.general import Set
from beanie.odm.queries.update import UpdateResponse


class Person(Document):
    name: str
    tag: str | None = None

    @before_event(Save, Update, Replace, SaveChanges)
    def set_tag(self):
        print("    before_event TRIGGERED")
        self.tag = "updated"


async def main():
    client = AsyncIOMotorClient("mongodb://localhost:27017")
    client.get_io_loop = asyncio.get_running_loop
    await init_beanie(
        client["mydb"],
        document_models=[
            Person,
        ],
    )

    print("=== create")
    await Person(name="Alice").insert()
    await Person(name="Bob").insert()
    await Person(name="Charlie").insert()
    await Person(name="Dan").insert()

    print("=== find_one.update")
    result = await Person.find_one(Person.name == "Alice").update(Set({"name": "Alicia"}), response_type=UpdateResponse.NEW_DOCUMENT)
    print(f"    result: {result}")

    print("=== find_one; update")
    result = await Person.find_one(Person.name == "Bob")
    result = await result.update(Set({"name": "Bobby"}))
    print(f"    result: {result}")

    print("=== find_one; set")
    result = await Person.find_one(Person.name == "Charlie")
    result = await result.set({"name": "Charles"})
    print(f"    result: {result}")

    print("=== find_one; save")
    result = await Person.find_one(Person.name == "Dan")
    result.name = "Daniel"
    await result.save()
    print(f"    result: {result}")

    print("=== close")
    client.close()

if __name__ == "__main__":
    asyncio.run(main())

Expected behavior
I'm unsure of whether or not the before_event should be triggered twice during the 4th case (find, update, save()), but for all 4 cases I would expect the before_event to get triggered at least once, and I would expect the final value in the DB to have a "tag": "updated" value.

Additional context
I'm particularly interested in the behavior of the first case, where .update() is called directly on the result of find_one() - I would like to use this pattern with a before_event annotation to automatically set an updatedAt field on my documents.

The repro code can be run with beanie installed and an empty mongodb instance (I used the mongo:5 docker image, but I suspect a local instance would work as well).

Python version: 3.10.10
Beanie version: 1.28.0