docs: Skip micro upgrade instructions
docs: Skip micro upgrade instructions

Releases v1.6.7 and v1.7.1 violated the constraint that a direct image
update can be performed to update to the newer version, due to a change
that required both an image change as well as a change in the templates.

This will be simpler for all involved if we move towards using Helm (or
at least Helm templates) for all releases.

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

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