docs: changelog 4.0.21

Author: soyuka

CHANGELOG.md

@@ -1,5 +1,16 @@
 # Changelog
 
+## v4.0.21
+
+### Bug fixes
+
+* [7cb5a6db8](https://github.com/api-platform/core/commit/7cb5a6db87241d95e6c324318fe861bd4f1820cf) fix: allow parameter provider as object (#7032)
+* [bb83e9a03](https://github.com/api-platform/core/commit/bb83e9a034c511156aa20a8555bf367374ef5458) fix(symfony): allow to merge array with string in global defaults (#7037)
+* [da2e86809](https://github.com/api-platform/core/commit/da2e86809d4a8dec294dc2fc148d92406f1f7fd1) fix: header parameter should be case insensitive (#7031)
+
+
+### Features
+
 ## v4.0.20
 
 ### Bug fixes