docs: Update requirements for backporting
docs: Update requirements for backporting

Since we want to move forward with using the GitHub CLI for creating
backports, the previously listed optional items are actually required.

Signed-off-by: Chris Tarazi <711c73f64afdce07b7e38039a96d2224209e9a6c@isovalent.com>

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