No Errors for Invalid or Missing Sprite Names in `layers` option in `goboscript.toml`

[aspizu]

Summary

Specifying a sprite name in layers that does not exist in the project produces no error.
Not specifying all sprite names in layers produces no error.

Steps to Reproduce

layers = ["nonexistent_sprite"]

Expected Behavior

A compile error should be raised for each sprite name in layers that does not correspond to an existing sprite, or is missing a name for a sprite that does exist.

Actual Behavior

No error is produced.