doc: edit "Involving the TSC"

Edit the "Involving the TSC" section of the Collaborator Guide to reduce
passive voice, make things concise, etc.

PR-URL: https://github.com/nodejs/node/pull/26481
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Yuta Hiroto <hello@hiroppy.me>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

COLLABORATOR_GUIDE.md

@@ -374,13 +374,12 @@ deprecation level of an API.
 ### Involving the TSC
 
 Collaborators may opt to elevate pull requests or issues to the [TSC][].
-This should be done where a pull request:
+Do this if a pull request or issue:
 
 - is labeled `semver-major`, or
 - has a significant impact on the codebase, or
-- is inherently controversial, or
-- has failed to reach consensus amongst the Collaborators who are
-  actively participating in the discussion.
+- is controversial, or
+- is at an impasse among Collaborators who are participating in the discussion.
 
 Assign the `tsc-review` label or @-mention the
 `@nodejs/tsc` GitHub team if you want to elevate an issue to the [TSC][].