Apply suggestion from @jderusse

Author: jderusse

src/Service/S3/CHANGELOG.md

@@ -2,9 +2,9 @@
 
 ## NOT RELEASED
 
-### Added
+### BC-BREAK
 
-- AWS api-change: This release includes backward compatibility work on the "Expires" parameter.
+- AWS api-change: Expires's property and its getters/setters switched from `\DateTimeImmutable` to `string`.
 
 ## 2.10.0
 

src/Service/S3/composer.json

@@ -30,7 +30,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "2.11-dev"
+            "dev-master": "3.0-dev"
         }
     }
 }