Refactor helper functions and update seeders

- Simplified `tmpostChannel` and `tmpostDefaultInventory` functions by removing caching logic.
- Changed return type of `namesWithTaxes` method in `CategoryRepository` to `mixed`.
- Enabled `ProductsTableSeeder` and added user association logic for product relations.
- Updated `BrandsSeeder` to include the product ID in the slug.
- Added `old_customer_id` to `options` in `SellersTableSeeder` for user tracking.

app/Repositories/Ecommerce/Product/Category/CategoryRepository.php

@@ -124,7 +124,7 @@ class CategoryRepository
     /**
      * Names with taxes (usefull for nova)
      */
-    public static function namesWithTaxes(): array
+    public static function namesWithTaxes(): mixed
     {
         return CacheRepository::make(
             time: 5,