PROCESS CHANGE: Outdated files

[aliok]

• There are emeritus leads in the https://github.com/knative/community/blob/main/peribolos/knative-OWNERS_ALIASES file. It is bad practice to have inactive people in that list.
• There are some WGs and task forces which are now obsolete/inactive: docs, conformance-task-force, trademark-committee (we have work in progress to remove this one)
• Similarly, there are emeritus leads in this file: https://github.com/knative/community/blob/main/groups/groups.yaml