gdk-pixbuf: Enable gobject introspection

Signed-off-by: Kieran Ramos <ramos.kieran@gmail.com>
atk: Enable gobject introspection

Signed-off-by: Kieran Ramos <ramos.kieran@gmail.com>
gtk+3: Enable gobject introspection

Signed-off-by: Kieran Ramos <ramos.kieran@gmail.com>
pango: Enable gobject introspection

Signed-off-by: Kieran Ramos <ramos.kieran@gmail.com>
gobject-introspection: Override GOBJECT_INTROSPECTION_LIBDIR

Signed-off-by: Kieran Ramos <ramos.kieran@gmail.com>
gobject-introspection: Add optional tests

Signed-off-by: Kieran Ramos <ramos.kieran@gmail.com>
pygobject3: Add formula for 3.8.3

Due to the major bump, we have retained the pygobject 2.0 line.

Signed-off-by: Kieran Ramos <ramos.kieran@gmail.com>
pygobject3: Add tests

Signed-off-by: Kieran Ramos <ramos.kieran@gmail.com>
pygobject3: Fix XDG_DATA_DIRS

Signed-off-by: Kieran Ramos <ramos.kieran@gmail.com>
py3cairo: Add formula for py3cairo 1.10.0. This seems necessary as `pip3 install pycairo` failed to install. The name py3cairo matches what Debian uses but disagrees with the developers calling it pycairo; however, the pygobject and other projects look for py3cairo.

Signed-off-by: Kieran Ramos <ramos.kieran@gmail.com>