Fish issue with dynamic themes

Once fish port gets bumped to [`151fc14cf21e5bd0ea335e475fc14de1b500d4f5`](https://github.com/catppuccin/fish/commit/151fc14cf21e5bd0ea335e475fc14de1b500d4f5), setting fish flavor to `Latte` will most likely fail. Should we add fish's Latte theme to be a "always light" theme? Otherwise, should we add an assertion or a default theme in case it is `Latte`?