Draft: Provide libgio-2.0-dev from libglib2.0-dev in bookworm

In unstable, libgio-2.0-dev has been split off from libglib2.0-dev. Some of the build dependencies on libglib2.0-dev will be switched over to libgio-2.0-dev. This causes them to be unsatisfiable in bookworm-backports. To reduce the negative effects of the split, the next bookworm update shall provide forward compatibility by providing libgio-2.0-dev (which has never been mentioned in bookworm).