x11-toolkits/gtksourceview5: update to 5.14.2
Changelog: https://gitlab.gnome.org/GNOME/gtksourceview/-/blob/master/NEWS
Reported by: Graham Perrin <grahamperrin@gmail.com>
Approved by: gnome (fluffy)
Co-authored-by: Yusuf Yaman <nxjoseph@protonmail.com>
PR: 283354