docs: Improve 1.9 helm options change upgrade notes
docs: Improve 1.9 helm options change upgrade notes

Try to make it more clear to users how they should specify the options
in the primary command for upgrading the deployment, to prevent them
from using 1.8.x helm options which are no longer recognized by Cilium
1.9 Helm charts.

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

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