update changelog (new upstream snapshot)

debian/changelog

@@ -1,13 +1,15 @@
-cloud-init (24.2-0ubuntu1~22.04.2) UNRELEASED; urgency=medium
+cloud-init (24.3.1-0ubuntu0~22.04.1) UNRELEASED; urgency=medium
 
   * d/p/no-single-process.patch: Remove single process optimization
   * d/p/no-nocloud-network.patch: Remove nocloud network feature
   * refresh patches:
     - d/p/cli-retain-file-argument-as-main-cmd-arg.patch
     - d/p/revert-551f560d-cloud-config-after-snap-seeding.patch
-  * Upstream snapshot based on upstream/main at edd92b71.
+  * Upstream snapshot based on 24.3.1. (LP: #2079224).
+    List of changes from upstream can be found at
+    https://raw.githubusercontent.com/canonical/cloud-init/24.3.1/ChangeLog
 
- -- Chad Smith <[email protected]>  Wed, 07 Aug 2024 16:36:13 -0600
+ -- Chad Smith <[email protected]>  Fri, 06 Sep 2024 10:00:47 -0600
 
 cloud-init (24.2-0ubuntu1~22.04.1) jammy; urgency=medium