[mutter] test: Remove unreferenced test-texture-rectangle

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 54ac1f6b592f21fa185e41dc9ef0f8faf14c1b3e
Author: Adam Jackson <ajax redhat com>
Date:   Wed Oct 23 11:12:22 2019 -0400

    test: Remove unreferenced test-texture-rectangle
    
    This isn't even built, and it's testing GL_TEXTURE_RECTANGLE_ARB, which
    is not even a code path we support anymore since we require real NPOT.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/883

 cogl/tests/conform/test-texture-rectangle.c | 276 ----------------------------
 1 file changed, 276 deletions(-)