Backend: Make build fail on wrong annotation

[CalMWolfs]

What

Make build fail when event functions have wrong annotation. This is because while both our own live plugin and the minecraft development plugin give warnings when you have the wrong annotation, neither of them will actually stop the build from finishing, and the build task that is run on prs does not get far enough into launching that it will crash. This means if a branch is updated and the person doesnt launch it, they will not know that it breaks. As we switch over events to the new system this makes it so that if I or another contributor updates a pr we can tell immediately that it does not build and needs attention making it so that we can identify prs that need fixing quicker.

Example error message:

w: [ksp] Function in at.hannibal2.skyhanni.features.inventory.HarpFeatures must have an event assignable from SkyHanniEvent because it is annotated with @HandleEvent
w: [ksp] Function in at.hannibal2.skyhanni.features.inventory.HarpFeatures must have an event assignable from SkyHanniEvent because it is annotated with @HandleEvent
w: [ksp] Function in at.hannibal2.skyhanni.features.inventory.HarpFeatures must have an event assignable from SkyHanniEvent because it is annotated with @HandleEvent
w: [ksp] Function in at.hannibal2.skyhanni.features.inventory.HarpFeatures must have an event assignable from Event because it is annotated with @SubscribeEvent
w: [ksp] Function in at.hannibal2.skyhanni.features.inventory.HarpFeatures must have an event assignable from SkyHanniEvent because it is annotated with @HandleEvent
w: [ksp] Function in at.hannibal2.skyhanni.features.inventory.HarpFeatures must have an event assignable from SkyHanniEvent because it is annotated with @HandleEvent
w: [ksp] Function in at.hannibal2.skyhanni.features.inventory.HarpFeatures must have an event assignable from SkyHanniEvent because it is annotated with @HandleEvent
w: [ksp] Function in at.hannibal2.skyhanni.features.inventory.HarpFeatures must have an event assignable from SkyHanniEvent because it is annotated with @HandleEvent

Changelog Technical Details

• Make build fail when event functions have wrong annotation. - CalMWolfs