doc: update still maintained badge for README

Badge on README.md saying of the project is still maintained or not is buggy. In addition the year in use was 2023, and we are in 2024.

Author: pylapp

README.md

@@ -1,7 +1,7 @@
 [![Opened issues](https://img.shields.io/github/issues-raw/Orange-OpenSource/floss-toolbox?style=for-the-badge)](https://github.com/Orange-OpenSource/floss-toolbox/issues)
 [![Apache 2.0 license](https://img.shields.io/github/license/Orange-OpenSource/floss-toolbox?style=for-the-badge)](https://github.com/Orange-OpenSource/floss-toolbox/blob/dev/LICENSE.txt)
 [![Versions](https://img.shields.io/github/v/release/Orange-OpenSource/floss-toolbox?label=Last%20version&style=for-the-badge)](https://github.com/Orange-OpenSource/floss-toolbox/releases)
-[![Still maintained](https://img.shields.io/maintenance/yes/2023?style=for-the-badge)](https://github.com/Orange-OpenSource/floss-toolbox/issues?q=is%3Aissue+is%3Aclosed)
+[![Still maintained](https://img.shields.io/maintenance/yes/2024?style=for-the-badge)](https://github.com/Orange-OpenSource/floss-toolbox/issues?q=is%3Aissue+is%3Aclosed)
 [![Code size](https://img.shields.io/github/languages/code-size/Orange-OpenSource/floss-toolbox?style=for-the-badge)](https://github.com/Orange-OpenSource/floss-toolbox)
 
 [![Shell](https://img.shields.io/badge/-Shell-89e051?style=for-the-badge)](https://github.com/Orange-OpenSource/floss-toolbox/search?l=shell)