ci: Use the same VK-GL-CTS tree for GL/GLES as VK.

There's no need to have separate build scripts here, just choose what the
DEQP_TARGET is for the particular container being built.  This brings in a
tremendous number of GLES test fixes that haven't made it into a tagged
gles CTS release.

Closes: #2056

Reviewed-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6526>
7 files changed