meta: remove collaborator self-nomination

Anyone with sufficient involvement in Node.js such that becoming a collaborator would benefit Node.js, is going to have plenty of people to ask. The self-nomination process has been entirely superfluous the entire time I've been involved in Node.js. Simplify things and get rid of it.

Author: Trott

GOVERNANCE.md

@@ -194,9 +194,11 @@ nominee publicly accepts it. In the case
 of an objection, the TSC is responsible for working with the individuals
 involved and finding a resolution.
 
-Collaborators might overlook someone with valuable contributions. In that case,
-the contributor may open an issue or contact a collaborator to request a
-nomination.
+There are steps a nominator can take in advance to make a nomination as
+frictionless as possible. To request feedback from other collaborators in
+private, use the [collaborators discussion page][]
+(which only collaborators may view). A nominator may also work with the
+nominee to improve their contribution profile.
 
 #### How to review a collaborator nomination