backporting: Make set-labels executable
backporting: Make set-labels executable

It's useful to make this script executable, to avoid having to prepend
"python" just to run it. Add the executable bit.

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

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