editors/neovim: Update to 0.12.1
Changes:
https://github.com/neovim/neovim/commit/7ac5a26d5633a41d7e291141488ca635242973a5
Restrict tests to unittest target while functionaltest target fails
Reviewed by: thierry (mentor)
Approved by: thierry (mentor)
Differential Revision: https://reviews.freebsd.org/D56359