Among other things, https://jira.mongodb.org/browse/SERVER-111008 removed the changeStreams server parameter, which was supposed to be used only with serverless change streams.

As the serverless change streams feature was never released, we assumed it would be safe to remove the server parameter as well.
However, it seems that this causes trouble when upgrading clusters from earlier versions to v8.3.
Upgrades that previously used this parameter can fail with errors such as (NoSuchKey) Unknown server parameter: changeStreams.

To support smooth upgrades to v8.3, we need to bring this parameter back, but as a stub that does nothing (potentially it could print a deprecation warning).