Error:
Installing dependencies from lock file (including require-dev)
Verifying lock file contents can be installed on current platform.
Warning: The lock file is not up to date with the latest changes in composer.json. You may be getting outdated dependencies. It is recommended that you run `composer update` or `composer update <package name>`.
Nothing to install, update or remove
Package fzaninotto/faker is abandoned, you should avoid using it. No replacement was suggested.
Generating optimized autoload files
Class App\Http\Controllers\PassportAPI\VenueController located in C:/xampp-new/htdocs/ds-company-10-ms/app\Http\Controllers\VenueController.php does not comply with psr-4 autoloading standard. Skipping.
Class App\Helpers\Helper located in C:/xampp-new/htdocs/ds-company-10-ms/app\Http\Helpers\Helpers.php does not comply with psr-4 autoloading standard. Skipping.
> Illuminate\Foundation\ComposerScripts::postAutoloadDump
> @php artisan package:discover
In cache.php line 91:
Call to undefined function str_slug()
Script @php artisan package:discover handling the post-autoload-dump event returned with error code 1

Solution:
f you have gone through theĀ upgrade guideĀ then you must know that
StringĀ andĀ ArrayĀ Helpers have beenĀ removedĀ from the Core Framework
So if You need to use the helper install the package
composer require laravel/helpers
and all the helpers are moved to this package
after that run Composer install