Globs don't get invalidated if a generated node changes whether it is output or not

[jakemac53]

The way we track globs today is only based off of new or deleted source files, and the generated asset nodes that affects.

The problem is we don't require you to actually output a node that you declare as an output, and if you change your decision then anything doing a glob that would select that file will not be invalidated.

This is going to be pretty difficult to resolve unfortunately without regressing performance severely, so we will have to put some thought into it.