.github/cilium-actions: remove github action helper message
.github/cilium-actions: remove github action helper message

Setting a label to avoid the PR from being merged should be sufficient
for a Cilium janitor to set the appropriate release note label of a
particular PR. Having a helper message might also be confusing for new
corners where they won't be able to set labels for a PR so it might be
confusing for them to fix the errors presented by the maintainer's
little helper.

Signed-off-by: André Martins <bc9800b9d52a24cce72a73dd528afed53f10e5fc@cilium.io>

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