Build Release Assets for all StyLua variants

[JohnnyMorganz]

We currently build release assets with all flags enabled (both luau and lua52). At the moment, this is fine, as there is no conflicting syntax between the two. The GitHub release assets are what are used for the VSCode extension, so the VSCode has all of this enabled.

We should create release assets for all variants individually (currently: lua51 [default], luau and lua52). We can then add a configuration option in the VSCode extension, to select which variant we want to use. Creating these release assets also means its easier for other users to quickly retrieve the variant they want from the releases page.

Need to see how this conflicts with https://github.com/Roblox/foreman, as its a commonly used toolchain manager in the Luau community, and foreman uses GitHub releases for its downloads.