[12.x] Improve Fluent Constructor Performance by Directly Assigning Attributes

[michaelnabil230]

This PR optimizes the constructor of the Fluent class by assigning the $attributes directly to the $this->attributes property, rather than using the fill() method.

Benchmark Results:

Version	Execution Time
Before	0.029 ms
After	0.002 ms

This change results in a more than 14x performance improvement, which is particularly beneficial in performance-critical applications where Fluent instances are frequently created.

The code for `Benchmark` is:

Benchmark::dd(
   fn() => Fluent::make(array_fill(0, 1000, 'Row')),
   5,
);

[crynobone]

Using fill() makes it inline with Eloquent Model:

framework/src/Illuminate/Database/Eloquent/Model.php

Line 278 in 22f61b3

$this->fill($attributes);

[taylorotwell]

Thanks for your pull request to Laravel!

Unfortunately, I'm going to delay merging this code for now. To preserve our ability to adequately maintain the framework, we need to be very careful regarding the amount of code we include.

If applicable, please consider releasing your code as a package so that the community can still take advantage of your contributions!