gitlab-ci: Use PAN_MESA_DEBUG=gles3 for Panfrost

We can drop now the GLES version overrides now that we have a DEBUG flag
that enables all what is expected from a GLES 3.0 implementation.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3950>
1 file changed