bug#66308: 30.0.50; DocView: Bump default value of doc-view-resolution

[Eli Zaretskii]

> Cc: 66308@debbugs.gnu.org, Stefan Kangas <stefankangas@gmail.com>,
>  Tassilo Horn <tsdh@gnu.org>
> Date: Tue, 03 Oct 2023 18:34:25 +0800
> From:  Po Lu via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> > Should we store this data on Unixes in `$XDG_CACHE_HOME` Instead
> > of temp?
> 
> Unix systems don't all provide XDG directories, and furthermore, storage
> considerations remain relevant there.

We have the file-system-info function, which we could use to determine
how much storage is available.