README.md: fix heading for enhancements spreadsheet section

The internal link was broken bc the heading was altered/didn't match.

Author: kikisdeliveryservice

README.md

@@ -78,7 +78,7 @@ Links:
 
 - [1.26 Milestone](http://bit.ly/k8s126-enhancements)
 
-## Enhancements Tracking Spreadsheet (deprecated)
+## Enhancements Tracking Spreadsheet
 
 Prior to the 1.26 release, enhancements from this repo were visualized using Enhancements Tracking Spreadsheets.