SDK7: Player entity position is not being updated correctly on every frame

When checking the player's position every frame (example code below) there are frames in which the system receives the same player position as the previous frame, even though the player is constantly moving...

### Example Code to reproduce the issue
```
let lastPlayerPos: Vector3 | undefined = undefined
export function playerPositionCheckSystem (dt: number) {
if (!Transform.has(engine.PlayerEntity)) return

const playerPos = Transform.get(engine.PlayerEntity).position
const moved = playerPos != lastPlayerPos

console.log(`player moved? ${moved}`)

lastPlayerPos = playerPos
}
engine.addSystem(playerPositionCheckSystem)
```
One example scene that suffers from this is the [avatar-swap test scene](https://github.com/decentraland-scenes/sdk7-goerli-plaza/tree/main/avatar-swap), affecting its character animations while moving.

### Possible Different Causes
- The renderer is sending wrong values on some frames
- The scene runtime / kernel is not reading the new values on every frame
- The system is being called twice in the same frame for some reason

Start with the playerPositionCheckSystem entry point, the Transform access on engine.PlayerEntity, and engine.addSystem in the reported example. Reproduce the behavior in the linked avatar-swap test scene while checking whether repeated positions come from the renderer or scene runtime. Done means player positions update on every frame and the affected character animations behave correctly while moving.

Written by the indexing model from the issue text.