Fix Table attribute incrementing not working for Pivot models

[sadique-cws]

Description

Fixes #59335

This PR solves an issue where using the #[Table] attribute on a Pivot model fails to configure its incrementing primary key property correctly. For regular model classes, the incrementing argument acts as a drop-in replacement layout over the classic $incrementing = true; property styling.

🚨 The core issue

Pivot models default to non-incrementing primary keys:

class Pivot extends Model {
    public $incrementing = false; // <-- Default false for Pivot
}

Inside Illuminate\Database\Eloquent\Model::__construct, there exists logic that attempts to sync attributes from #Table classes, but includes an isolated safeguard:

php

if ($this->incrementing === true) { // <-- ❌ Blocks override for values that start as false
     $this->incrementing = $tableAttribute->incrementing;
}

Because of this specific outer validation barrier, the static $incrementing = false definition explicitly placed inside the parent Pivot class overrides the attribute statement, locking the model fully from applying the toggle config back to true.

💡 Solution
I've updated the logic by removing the outer check. Eliminating the condition lets the #[Table] attribute function correctly as the universal source of truth for both basic model instances and Pivot model instances alike.