changelogs: Add entry for dynatrace div by zero fix (envoyproxy#40290)

Changelog for envoyproxy#40220

Signed-off-by: Ryan Northey <[email protected]>

Author: phlax

changelogs/current.yaml

@@ -11,7 +11,10 @@ bug_fixes:
 - area: release
   change: |
     Container (Ubuntu/distroless) updates, and fixed permissions for distroless config directory.
-
+- area: dynatrace
+  change: |
+    Fixed a division by zero bug in the Dynatrace sampling controller that occurred when ``total_wanted`` was less than
+    ``top_k_size``. The calculation was refactored to avoid the intermediate division that could result in zero.
 
 removed_config_or_runtime:
 # *Normally occurs at the end of the* :ref:`deprecation period <deprecated>`