doc: remove "How is an LTS release cut?" section

The release process is in the Release plan, linked earlier in the doc.
Don't include information here because duplicated information is likely
to drift apart, resulting in contradictions and a lack of clarity about
which document is correct. (I think the text removed is already
out-of-date. I could be wrong, and it doesn't much matter, as it should
be removed anyway.) It's also not entirely clear what the
utility/relevance of this information is in this particular document.

PR-URL: https://github.com/nodejs/node/pull/26955
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

COLLABORATOR_GUIDE.md

@@ -30,11 +30,8 @@
   - [I Made a Mistake](#i-made-a-mistake)
   - [Long Term Support](#long-term-support)
     - [What is LTS?](#what-is-lts)
-    - [How does LTS work?](#how-does-lts-work)
-    - [Landing semver-minor commits in LTS](#landing-semver-minor-commits-in-lts)
     - [How are LTS Branches Managed?](#how-are-lts-branches-managed)
     - [How can I help?](#how-can-i-help)
-    - [How is an LTS release cut?](#how-is-an-lts-release-cut)
 * [Who to CC in the issue tracker](#who-to-cc-in-the-issue-tracker)
 
 This document explains how Collaborators manage the Node.js project.
@@ -681,13 +678,6 @@ label.
 Attach the appropriate `lts-watch-` label to any PR that may impact an LTS
 release.
 
-#### How is an LTS release cut?
-
-When the LTS working group determines that a new LTS release is required,
-selected commits will be picked from the staging branch to be included in the
-release. This process of making a release will be a collaboration between the
-LTS working group and the Release team.
-
 ## Who to CC in the issue tracker
 
 | Subsystem                                | Maintainers                                                           |