update readme

Author: sarahmish

README.md

@@ -50,7 +50,7 @@ Features include:
 
 ## Requirements
 
-**MLBlocks** has been developed and tested on [Python 3.6, 3.7, 3.8, 3.9, 3.10, 3.11, 3.12, 3.13](https://www.python.org/downloads/)
+**MLBlocks** has been developed and tested on [Python 3.8, 3.9, 3.10, 3.11, 3.12, 3.13](https://www.python.org/downloads/)
 
 ## Install with `pip`