test: Ensure that verifier test runs on clean dir
test: Ensure that verifier test runs on clean dir

Clean the bpf/ directory at the beginning of the verifier tests, to
ensure that the datapath is freshly compiled during the test and that
version is validated (rather than some cached version from prior
compilation earlier in the build process).

Signed-off-by: Joe Stringer <16a9a54ddf4259952e3c118c763138e83693d7fd@cilium.io>

cilium-team/cilium,tklauser/cilium,tklauser/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium,tgraf/cilium,cilium-team/cilium,michi-covalent/cilium,tgraf/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,michi-covalent/cilium,tgraf/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,tgraf/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium