bug#50984: 28.0.60; define-child-mode warnings in semantic/bovine/el.el and semantic/bovine/c.el

[Stefan Kangas]

We have these warnings on emacs-28:

In toplevel form:
cedet/semantic/bovine/el.el:931:1: Warning: `define-child-mode' is an obsolete
    macro (as of 27.1); use `define-derived-mode' instead.
In toplevel form:
cedet/semantic/bovine/c.el:55:1: Warning: `define-child-mode' is an obsolete
    macro (as of 27.1); use `define-derived-mode' instead.

I don't know when these showed up, but I guess some time in the last 6
months as I can't remember seeing them before.  They have been there
since at least late August or so.

We have discussed and fixed similar warnings in 2019:
https://lists.gnu.org/archive/html/emacs-devel/2019-11/msg00748.html