Add check if "services.yml" file exists

Problem/Motivation

In the file web/sites/default/default.settings.php services file included

$settings['container_yamls'][] = $app_root . '/'. $site_path . '/services.yml';

but a check is not added to see whether this file exists or not.

Steps to reproduce

Download Drupal 10.3.0 and navigate to web/sites/default/default.settings.php
See line no 716 or check directly on git repo https://git.drupalcode.org/project/drupal/-/blob/10.3.x/sites/default/de...

Proposed resolution

Add a check using

file_exists()

Remaining tasks

Add the check.

User interface changes

NA

API changes

NA

Data model changes

NA

Release notes snippet

Thanks