Update _data/mentors.yml

Co-authored-by: Jennet Turkkan <67760504+jennethydyrova@users.noreply.github.com>

Author: khairahscorner

_data/mentors.yml

@@ -3089,7 +3089,7 @@
     - Backend Developer
     - Fullstack Developer
     - Distributed Systems
-    languages: C#, C#, C#, C#, C#
+    languages: C#
     focus:
     - Grow from beginner to mid-level
     - Change specialisation within IT