ci: bump version to v0.9.20

Author: github-actions[bot]

README.md

@@ -4,7 +4,7 @@
 Dart & Flutter Packages by dev-cetera.com & contributors.
 
 [![pub](https://img.shields.io/pub/v/df_generate_dart_models_core.svg)](https://pub.dev/packages/df_generate_dart_models_core)
-[![tag](https://img.shields.io/badge/tag-v0.9.21-purple)](https://github.com/dev-cetera/df_generate_dart_models_core/tree/v0.9.21)
+[![tag](https://img.shields.io/badge/tag-v0.9.20-purple)](https://github.com/dev-cetera/df_generate_dart_models_core/tree/v0.9.20)
 [![license](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/dev-cetera/df_generate_dart_models_core/main/LICENSE)
 
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