doc: remove How Does LTS Work section from Collaborator Guide

The How Does LTS Work section duplicates material in the release plan,
to which there is already a link in the doc. Unfortunately, it has gone
out of sync with the release plan, resulting in incorrect material being
in the Collaborator Guide. (The Release WG needs to approve certain
changes, not LTS WG as the guide currently says. It used to be the LTS
WG, but that changed.)

Instead of duplicating material in the Collaborator Guide and risking
that the two documents contradict each other again, instruct the reader
to refer to the release plan as the canonical source of information.

PR-URL: #26723
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

COLLABORATOR_GUIDE.md

@@ -639,20 +639,9 @@ git push upstream master
 
 Long Term Support (LTS) guarantees 30-month support cycles for specific Node.js
 versions. You can find more information
-[in the full release plan](https://github.com/nodejs/Release#release-plan).
-
-#### How does LTS work?
-
-Once a Current branch enters LTS, changes in that branch are limited to bug
-fixes, security updates, possible npm updates, documentation updates, and
-certain performance improvements that can be demonstrated to not break existing
-applications. Semver-minor changes are only permitted if required for bug fixes
-and then only on a case-by-case basis with LTS WG and possibly Technical
-Steering Committee (TSC) review. Semver-major changes are permitted only if
-required for security-related fixes.
-
-Once a Current branch moves into Maintenance mode, only **critical** bugs,
-**critical** security fixes, and documentation updates will be permitted.
+[in the full release plan](https://github.com/nodejs/Release#release-plan). Once
+a branch enters LTS, the release plan limits the types of changes permitted in
+the branch.
 
 #### Landing semver-minor commits in LTS