doc: shorten pull request wait time to 48 hours

Currently, we have a 72 rule for how many hours a pull request should
be left open at a minimum. Reduce that time to 48 hours.

PR-URL: #23082
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>

COLLABORATOR_GUIDE.md

@@ -171,7 +171,7 @@ agenda.
 ### Waiting for Approvals
 
 Before landing pull requests, sufficient time should be left for input
-from other Collaborators. In general, leave at least 72 hours to account for
+from other Collaborators. In general, leave at least 48 hours to account for
 international time differences and work schedules. However, certain types of
 pull requests can be fast-tracked and may be landed after a shorter delay. For
 example:

doc/onboarding.md

@@ -138,7 +138,7 @@ onboarding session.
   * There is a minimum waiting time which we try to respect for non-trivial
     changes so that people who may have important input in such a distributed
     project are able to respond.
-  * For non-trivial changes, leave the pull request open for at least 72 hours.
+  * For non-trivial changes, leave the pull request open for at least 48 hours.
   * If a pull request is abandoned, check if they'd mind if you took it over
     (especially if it just has nits left).
 * Approving a change
@@ -214,7 +214,7 @@ needs to be pointed out separately during the onboarding.
 * Run CI on the PR. Because the PR does not affect any code, use the
   `node-test-pull-request-lite-pipeline` CI task.
 * After one or two approvals, land the PR (PRs of this type do not need to wait
-  for 72 hours to land).
+  for 48 hours to land).
   * Be sure to add the `PR-URL: <full-pr-url>` and appropriate `Reviewed-By:`
     metadata.
   * [`node-core-utils`][] automates the generation of metadata and the landing