Replaced macos-15-intel from macos-13 and added macos-15 (#198) #567

Job	Run time
ruby-versions / Generate Ruby versions	5s
windows-latest 2.7	2m 7s
windows-latest 3.1	1m 45s
windows-latest 3.0	1m 31s
windows-latest 3.3	2m 15s
windows-latest 3.2	2m 8s
windows-latest mingw	1m 41s
windows-latest 3.4	1m 26s
windows-latest jruby-head	2m 5s
windows-latest mswin	1m 32s
	16m 35s

Provide feedback