Reconcile Developer on-call with on-call page

We recently launched this:

• https://about.gitlab.com/handbook/engineering/development/processes/Infra-Dev-Escalation/
• https://about.gitlab.com/handbook/engineering/development/processes/Infra-Dev-Escalation/process.html

We also have this: https://about.gitlab.com/handbook/on-call/

Can we interlink the two at a minimum, or work towards a SSoT? the on-call page already has SRE and Security, so consolidating there makes sense.

CC @clefelhocz1