add news bullet

Author: teunbrand

NEWS.md

@@ -1,7 +1,7 @@
 # ggplot2 (development version)
 
-### Bug fixes
-
+* Fixed regression where the first (unnamed) argument to colour/fill scales was 
+  not passed as the `name` argument (@teunbrand, #6623)
 * Fixed regression where `draw_key_rect()` stopped using `fill` colours 
   (@mitchelloharawild, #6609).
 * Fixed regression where `scale_{x,y}_*()` threw an error when an expression