doc: enforce strict policy to semver-major releases

Co-authored-by: Antoine du Hamel <duhamelantoine1995@gmail.com>
PR-URL: #55732
Refs: nodejs/Release#1054
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Ulises Gascón <ulisesgascongonzalez@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>

doc/contributing/releases.md

@@ -1217,8 +1217,14 @@ the releaser, these must be kept in sync with `main`.
 The `vN.x` and `vN.x-staging` branches must be kept in sync with one another
 up until the date of the release.
 
-The TSC should be informed of any `SEMVER-MAJOR` commits that land within one
-month of the release.
+If a `SEMVER-MAJOR` pull request lands on the default branch within one month
+prior to the major release date, it must not be included on the new major
+staging branch, unless there is consensus from the Node.js releasers team to
+do so. This measure aims to ensure better stability for the release candidate
+(RC) phase, which begins approximately two weeks prior to the official release.
+By restricting `SEMVER-MAJOR` commits in this period, we provide more time for
+thorough testing and reduce the potential for major breakages, especially in
+LTS lines.
 
 ### Create release labels