[Regression] Variant parser fails on nested dictionaries

[Aylur]

Description

With the original parser code from @ewlsh this used to be parsed correctly:

// { [key: string]: { [key: string]: unknown } }
type NestedDict = $ParseRecursiveVariant<"a{sa{sv}}">

With the changes introduced in #279 it now fails with an error.

Another change I failed to notice from the PR is that v type (aka GLib.Variant<any>) unpacks to any where in the original code it used to unpack to unknown which I feel like was more appropriate.

[JumpLink]

@Aylur Thanks for the bug report. I would appreciate it if you could try something here. Since most changes are made via the template, it should be relatively easy to try this out. I'm happy to help 😊