docs: update outdated v3 references to v4 in CONTRIBUTING.md

Signed-off-by: Rishav <bansalrishav047@gmail.com>

CONTRIBUTING.md

@@ -116,14 +116,14 @@ that we're already aware of. It is also worth asking on the Slack channels.
 
 ## Milestones
 
-We use milestones to track progress of specific planned releases.
+We use milestones to track progress of specific planned releases. Helm v4 is the current stable release.
 
-For example, if the latest currently-released version is `3.2.1`, an issue/PR which pertains to a
+For example, if the latest currently-released version is `4.0.0`, an issue/PR which pertains to a
 specific upcoming bugfix or feature release could fall into one of two different active milestones:
-`3.2.2` or `3.3.0`.
+`4.0.1` or `4.1.0`.
 
-Issues and PRs which are deemed backwards-incompatible may be added to the discussion items for
-Helm 4 with [label:v4.x](https://github.com/helm/helm/labels/v4.x). An issue or PR that we are not
+Issues and PRs which are deemed backwards-incompatible may be added to the next major version discussion
+with [label:v4.x](https://github.com/helm/helm/labels/v4.x). An issue or PR that we are not
 sure if we will be addressing will not be added to any milestone.
 
 A milestone (and hence release) can be closed when all outstanding issues/PRs have been closed