fix: remove version field from composer.json

Remove the version field that was added during release process.
Composer packages should use Git tags for versioning.

Author: dannorthern

composer.json

@@ -52,6 +52,5 @@
     }
   },
   "minimum-stability": "dev",
-  "prefer-stable": true,
-  "version": "3.2.1"
+  "prefer-stable": true
 }