Move changelog entry to new version

CHANGELOG.md

@@ -5,9 +5,12 @@ When adding entries, please treat them as if they could end up in a release any
 
 Thank you!
 
-# 0.18.24
+# 0.18.25
 
 * Fixes a regression from 0.18.4 which incorrectly rendered default values for certain types (see [#1593](https://github.com/disneystreaming/smithy4s/pull/1593))
+
+# 0.18.24
+
 * Adds missing nanoseconds in Document encoding of EPOCH_SECOND timestamps
 * Add support for `alloy#jsonUnknown`, allowing structures to capture unknown JSON fields in one of their members.
 * Add `getMessage` implementation in `Smithy4sThrowable` which will be overridden in cases where the error structure contains a message field, but otherwise will be used to prevent a useless `null` result when `getMessage` is called.