docs: fix ginkgo installation instructions
docs: fix ginkgo installation instructions

Signed-off-by: Martynas Pumputis <b14a8f953b021d09d1aafdca53cb27d7d9cede0c@covalent.io>

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