ci: Uprev deqp-runner and piglit.

deqp-runner uprevved to reduce memory usage on HW runners, let us experiment with shader cache on tmpfs, and hopefully provide a tool for virgl to be able to plausibly run piglit under crosvm instead of vtest.

piglit uprevved to avoid a flake in softpipe in glx-multithread-texture, and improve performance of the test, too!