The source project of this merge request has been removed.
gparamspec: mark nick/blurb as nullable
GParamSpec nicks and blurbs are effectively a deprecated feature,
or at least unused by most libraries these days. Since a number
of C libraries (i.e. GTK4) have started to null these out, annotate
them as (nullable) so bindings can do the same.
Closes #2719 (closed)