remove a custom bpftrace from the ubuntu 20.04 image
remove a custom bpftrace from the ubuntu 20.04 image

bpftrace in ubuntu 22.04 passes with t/90dtrace.t,
so we no longer need a patched one.

h2o/h2o,h2o/h2o,h2o/h2o,h2o/h2o,h2o/h2o,h2o/h2o,h2o/h2o,h2o/h2o,h2o/h2o