Revert "misc/gtk: move gtkrc-2.0"

[nezia1]

Reverts #118, as in the path type expects an absolute path so the type will not work with our use-case and breaks Hjem for everyone. I apologize for merging this, I thought the path type would work here.

I believe we do have to run asserts to check if it's a path-like string, but we cannot use the path type

[alfarelcynthesis]

The default is notably also invalid, so the entire gtk module in main is currently broken and not easily fixable without modifying option declarations to change the type.

[GetPsyched]

Since this was broken, I'd assume there's no need for mkRemovedOptionModule.

I'd want a breaking change like this to roll-forward instead of rolling-back, but might be acceptable still given a part of the module was broken.