Update default gems list at 36a3899e9d [ci skip]

NEWS.md

@@ -85,7 +85,7 @@ The following default gems are updated.
 * erb 4.0.3
 * fiddle 1.1.2
 * fileutils 1.7.1
-* irb 1.7.4
+* irb 1.8.0
 * nkf 0.1.3
 * optparse 0.4.0.pre.1
 * psych 5.1.0