CoglMatrix already is a typedef to graphene_matrix_t. This commit
simply drops the CoglMatrix type, and align parameters. There is
no functional change here, it's simply a find-and-replace commit.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1439
We're moving towards not supporting stand-alone application style
clutter stages, meaning the stage tests use will be reused instead of
recreated. To make this feasable, tests must clean up after themself.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1364