docs: fix building with meson 0.61.1
I got the following errors when trying to build with meson 0.61.1: [1] docs/polkit/meson.build:18:6: ERROR: gnome.gtkdoc keyword argument 'gobject_typesfile' was of type array[File] but should have been array[str] [2] docs/polkit/meson.build:18:6: ERROR: gnome.gtkdoc keyword argument 'html_assets' was of type array[File] but should have been array[str]
Writing polkit-1.types explicitly because there is only one such file. Moved html_images into another file because this variable is used only there.
I had to prefix image paths with "../" because otherwise I got: [3] No such file or directory: '/tmp/abf/rpmbuild/BUILD/polkit-0.119/docs/polkit/polkit-architecture.png'
It is a quick fix that I had to make just to build polkit with a fix of CVE-2021-4034 applied, please fix meson in a better way if needed.
Signed-off-by: Mikhail Novosyolov m.novosyolov@rosalinux.ru