Preparing for next development iteration, 3.3.1.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: dblock

CHANGELOG.md

@@ -1,3 +1,7 @@
+### 3.3.1 (Next)
+
+* Your contribution here.
+
 ### 3.3.0 (2026/10/09)
 
 * [#607](https://github.com/slack-ruby/slack-ruby-client/pull/607): Support non-rewindable Rack 3 request bodies when verifying Events API signatures, with WEBrick integration coverage; follows [#515](https://github.com/slack-ruby/slack-ruby-client/pull/515) - [@olleolleolle](https://github.com/olleolleolle), [@dblock](https://github.com/dblock).

README.md

@@ -70,7 +70,7 @@ A Ruby client for the Slack [Web](https://api.slack.com/web) and [Events](https:
 
 ## Stable Release
 
-You're reading the documentation for the **stable** release of slack-ruby-client, 3.3.0. See [UPGRADING](UPGRADING.md) when upgrading from an older version.
+You're reading the documentation for the **next** release of slack-ruby-client. Please see the documentation for the [last stable release, v3.3.0](https://github.com/slack-ruby/slack-ruby-client/blob/v3.3.0/README.md) unless you're integrating with HEAD. See [UPGRADING](UPGRADING.md) when upgrading from an older version.
 
 ## Installation
 

lib/slack/version.rb

@@ -1,4 +1,4 @@
 # frozen_string_literal: true
 module Slack
-  VERSION = '3.3.0'
+  VERSION = '3.3.1'
 end