Log Message:
at-spi2-atk: update to 2.26.1.

What's new in at-spi2-atk 2.26.1:

* meson: Ensure paths written to .pc file are absolute.

* Package a couple of missing meson.build files.

What's new in at-spi2-atk 2.25.3:

* Add error-message, error-for, details, and details-for relation types

* Add Meson build system (thanks to Emmanuele Bassi).

What's new in at-spi2-atk 2.25.2:

* Fix use after free when returned objects hold only one ref (bgo#781716).

* Add some missing roles to correspond with atk (description list,
  description term, description value, and footnote).