update README file

Author: NicosNicolaou16

README.md

@@ -14,5 +14,5 @@ https://developers.google.com/ml-kit/vision/barcode-scanning/code-scanner#java <
 
 Target SDK version: 35 <br />
 Minimum SDK version: 28 <br />
-Kotlin version: 2.0.21 <br />
+Kotlin version: 2.1.0 <br />
 Gradle version: 8.7.2 <br />