chore: bump emqx_utils version && changes

apps/emqx_utils/src/emqx_utils.app.src

@@ -2,7 +2,7 @@
 {application, emqx_utils, [
     {description, "Miscellaneous utilities for EMQX apps"},
     % strict semver, bump manually!
-    {vsn, "5.0.5"},
+    {vsn, "5.0.6"},
     {modules, [
         emqx_utils,
         emqx_utils_api,

changes/ce/perf-11399.en.md

@@ -0,0 +1,8 @@
+Improved the placeholder syntax of rule engine.
+
+The parameters of actions support using placeholder syntax to
+dynamically fill in the content of strings. The format of the
+placeholder syntax is `${key}`.
+Before this improvement, the `key` in `${key}` could only contain
+letters, numbers, and underscores. Now the `key` supports any UTF8
+characters.