Second part of #791. This PR builds off of #827.
Remarks:

• Ideally the NLua submodule should be updated to .NET 8 as well before merging this, but its not strictly required.
• This change is known to cause issues in regards to code mod building (mods will have to change their TargetFramework entry to net8.0 in order to build with this version of everest), already built mods aren't affected though.
• MacOS support for low 10.x. versions is unknown currently but the game has been ran on a vm and successfully booted.
• TASes have been tested against this version and are known to sync.
• Added a new log statement in order to facilitate the diagnosis of issues related to the runtime version upgrade.