Update CHANGELOG

Author: numbata

CHANGELOG.md

@@ -7,7 +7,7 @@
 #### Fixes
 
 * Your contribution here.
-
+* [#388](https://github.com/ruby-grape/grape-entity/pull/388): Drop ruby-head from test matrix to keep builds stable - [@numbata](https://github.com/numbata).
 
 ### ### 1.0.1 (2024-04-10)