at-spi2-core: update 2.46.0 -> 2.48.0

at-spi2-core: update 2.46.0 -> 2.48.0

What's new in at-spi2-core 2.48.0:

* Add a "atk-only" build option. This allows atk to be built without libdbus
  installed, but it does not build libatspi or the atk bridge.

* Fix some typos in the documentation.

What's new in at-spi2-core 2.47.90:

* Downgrade meson requirement to 0.63.

*  at-spi-dbus-bus service: set stop timeout to 5s

* Fix possible crash in screen_reader_signal_watcher.

What's new in at-spi2-core 2.47.1:
* The meson options -Dx11 and -Dintrospection are now implemented with
  meson features - https://mesonbuild.com/Build-options.html#features

  Instead of accepting values of "yes/no/auto", they take
  "enabled/disabled/auto".  Please change your build scripts
  accordingly if you use these options.

* Use gi-docgen to generate documentation.

* Register key grabs using the focused window, rather than the root window.
  This should prevent the window from losing focus when a key grab is used.

* atk-adaptor: Handle sockets in GetChildren.

* Improve documentation of the dbus interfaces.

* Various code clean-ups. Some unused code has been removed.

Signed-off-by: Markus Volk <f_l_k@t-online.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>