glib-2.0: Upgrade 2.78.5 -> 2.78.6

Handle regression of CVE-2024-34397 fix.

News (https://gitlab.gnome.org/GNOME/glib/-/commit/d40f72e98e4734ba826ba9a278814530720ba760

):

Overview of changes in GLib 2.78.6, 2024-05-08
==============================================
* Fix a regression with IBus caused by the fix for CVE-2024-34397 (#3353,
  work by Simon McVittie)
* Bugs fixed:
  - #3353 Fixing CVE-2024-34397 caused regressions for ibus (Simon McVittie)
  - !4056 Backport !4053 “gdbusconnection: Allow name owners to have the syntax
    of a well-known name” to glib-2-78

Signed-off-by: Peter Marko <peter.marko@siemens.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>