panfrost/ci: Turn redundant GLESCTS-full run into disabled Piglit job
The panfrost-g610-gl-full:arm64 was identical to the merge job, panfrost-g610-gl:arm64. Turn the -full job into a Piglit job, but keep it disabled until it gets more stable.
The quick Piglit testrun I did: https://gitlab.freedesktop.org/Valentine/mesa/-/jobs/67891493
Cc: @vigneshraman @kusma