fix: correct composer.json version and add version-bumper config

The version field in composer.json was stuck at 2.1.0 since it was added,
causing Packagist to not publish 2.2.0 and 2.2.1. Add composer.json to
version-bumper filesToModify so future releases bump it automatically.

Author: konradmichalik

composer.json

@@ -5,7 +5,7 @@
 		"GPL-2.0-or-later"
 	],
 	"type": "typo3-cms-extension",
-	"version": "2.1.0",
+	"version": "2.2.1",
 	"authors": [
 		{
 			"name": "Konrad Michalik",

version-bumper.yaml

@@ -1,5 +1,11 @@
 presets:
   - name: typo3-extension
 
+filesToModify:
+  - path: composer.json
+    patterns:
+      - '"version": "{%version%}"'
+    reportUnmatched: true
+
 releaseOptions:
   commitMessage: 'release: version {%version%}'