enchant2: update to 2.6.5.

2.6.5 (January 7, 2024)
-----------------------

This version permits error messages from spelling providers not to be valid
UTF-8. This allows error messages in particular about invalid UTF-8
characters in personal wordlists to be shown to the user. Developers take
note!

The --with-hunspell-dir configure option is removed (along with all the
other ---with-PROVIDER-dir options, which did nothing). Users who have
Hunspell dictionaries in non-standard locations should set the
Hunspell-specific environment variable DICPATH, or copy the dictionaries
into their user窶冱 Enchant configuration directory (for example
~/.config/enchant/hunspell).

Doxygen API documentation is now included in the release tarball (it is also
now available online).

(wiz)