Update bundled gems list at 4b5bcba [ci skip]

Author: matzbot

NEWS.md

@@ -24,6 +24,7 @@ The following bundled gems are promoted from default gems.
 * irb 1.15.1
 * reline 0.6.0
 * readline 0.0.4
+* fiddle 1.1.6
 
 We only list stdlib changes that are notable feature changes.