[committed] Switch to UTF-8 for INSTALL

[Joseph Myers]

On Thu, 29 Jun 2023, Siddhesh Poyarekar via Libc-alpha wrote:

> -   * GNU 'texinfo' 4.7 or later
> +   • GNU ‘texinfo’ 4.7 or later

Will all Texinfo versions supported for building glibc generate the 
desired INSTALL file?  If not, I think there should be some additional 
statement about versions to use when regenerating INSTALL.

For the versions that generate the UTF-8 INSTALL file, is the file 
generated independent of the locale used for the build (and, in 
particular, of whether that locale is a UTF-8 locale)?

-- 
Joseph S. Myers
joseph@codesourcery.com