minor #135 prepare release 0.3.0 (xabbuh)

This PR was merged into the 0.2-dev branch.

Discussion
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prepare release 0.3.0

Commits
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a9d9fb9 prepare release 0.3.0

Author: xabbuh

CHANGELOG.md

@@ -4,6 +4,7 @@ CHANGELOG
 0.3.0
 -----
 
+* allow `psr/container` 2.0
 * drop support for Symfony 5.3
 * drop support for PHP 7.2 and 7.3
 

composer.json

@@ -50,7 +50,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-main": "0.2-dev"
+            "dev-main": "0.3-dev"
         }
     }
 }