Update Cobalt to 0.8.0

- Update Cobalt to 0.8.0, switching our Lua version to 5.2(ish).

 - Remove our `load` wrapper, as we no longer need to inject _ENV into
   the enviroment table.

 - Update the parser to handle labels and goto. This doesn't check that
   gotos are well formed, but at least means the parser doesn't fall
   over on them.

 - Update our docs to reflect the changes to Cobalt.

buildSrc/src/main/kotlin/cc-tweaked.java-convention.gradle.kts

@@ -57,7 +57,6 @@ repositories {
 
         filter {
             includeGroup("cc.tweaked")
-            includeModule("org.squiddev", "Cobalt")
             // Things we mirror
             includeGroup("commoble.morered")
             includeGroup("dev.architectury")