Remove site-configuration script in main

[DawoudSheraz]

The ask originated from #1202 where the custom startup present in edx-platform was removed in favor of django startup. site-configuration script is used to setup site objects in platform and this script provides a wrapper for that. It is used in tutor-mfe and tutor-discovery. To be able to remove the script from core, we need to ensure tutor-mfe and tutor-discovery are not using site-configuration script and maybe use another way to do so. See https://openedx.slack.com/archives/CGE253B7V/p1740516391296149 for some context, such as why tutor-mfe site-configuration usage might be removable all together.

• Ensure tutor-discovery main is updated to stop using site-config and has an alternative in place if needed
• Ensure tutor-mfe main is updated to stop using site-config and has an alternative in place if needed
• Once above items are done, remove site configuration from main branch