Refactor: time to say good-bye to Lune

As of late - my understanding of Lune has changed, I no longer consider it a viable candidate for the target Luau runtime for Discord-Luau. This isn’t a fault of Lune - it's still an amazing piece of software - but rather a result of my own over-optimism about its future direction. Its priorities simply don’t align with the requirements of Discord-Luau. I’m not eager to switch away from Lune immediately, but a few emerging runtimes have caught my interest: 1. Zune: _Zune offers all the features of Lune along with additional capabilities - such as UDP sockets, process signals, and FFI - that I’ve been waiting for._ 2. Cart: _Although still under heavy development, Cart aims to be a general-purpose runtime, making it a potential alternative to Zune._ 3. Lute: _Lute is promising. However, its plan to build a package manager complicates its fit for Discord-Luau. Despite its supportive community, too many uncertainties mean I think this is the riskiest Runtime at the moment_ i. i want to clarify quickly, the work being put in by the team behind Lute is awesome, but I need this runtime to mature a bit before I decide if it's a good idea to use it or not. For now, I will continue using Lune while keeping an eye on these alternatives. My goal is to eventually implement support for one of them, ensuring that users looking for a Luau runtime for general-purpose programming aren’t directed to a platform that wasn’t designed for that purpose. ###### *It's also worth noting that Discord-Luau will maintain support for as many Runtimes as it can, but will only guarantee support for a specific Runtime, it's that this ticket is trying to find a match for.. ###### ** Last note - even after switching to an alternative Runtime, I may end up switching again in the future - I may find that once the general purpose Luau scene has matured a bit - alternative options may pop up