Merge pull request #540 from flori/remove-ruby-1-8 #144

Job	Run time
ruby-versions / Generate Ruby versions	2s
ubuntu-20.04 2.3	2m 11s
ubuntu-20.04 2.4	1m 25s
ubuntu-20.04 2.5	1m 23s
ubuntu-20.04 2.6	1m 23s
ubuntu-20.04 2.7	1m 36s
ubuntu-20.04 3.0	1m 13s
ubuntu-20.04 3.1	30s
ubuntu-20.04 3.2	54s
ubuntu-20.04 head	47s
ubuntu-20.04 jruby	1m 24s
ubuntu-20.04 jruby-head	1m 49s
ubuntu-20.04 truffleruby	1m 32s
ubuntu-20.04 truffleruby-head	1m 20s
ubuntu-22.04 2.3	1m 59s
ubuntu-22.04 2.4	1m 37s
ubuntu-22.04 2.5	1m 9s
ubuntu-22.04 2.6	1m 38s
ubuntu-22.04 2.7	1m 42s
ubuntu-22.04 3.0	26s
ubuntu-22.04 3.1	51s
ubuntu-22.04 3.2	21s
ubuntu-22.04 head	24s
ubuntu-22.04 jruby	2m 7s
ubuntu-22.04 jruby-head	1m 20s
ubuntu-22.04 truffleruby	1m 1s
ubuntu-22.04 truffleruby-head	1m 17s
macos-11 2.3	2m 41s
macos-11 2.4	2m 13s
macos-11 2.5	2m 58s
macos-11 2.6	3m 56s
macos-11 2.7	2m 57s
macos-11 3.0	40s
macos-11 3.1	42s
macos-11 3.2	41s
macos-11 head	40s
macos-11 jruby	1m 37s
macos-11 jruby-head	1m 22s
macos-11 truffleruby	1m 50s
macos-11 truffleruby-head	1m 41s
macos-12 2.3	2m 6s
macos-12 2.4	2m 7s
macos-12 2.5	2m 11s
macos-12 2.6	3m 22s
macos-12 2.7	3m 2s
macos-12 3.0	48s
macos-12 3.1	39s
macos-12 3.2	49s
macos-12 head	1m 51s
macos-12 jruby	2m 4s
macos-12 jruby-head	1m 23s
macos-12 truffleruby	1m 35s
macos-12 truffleruby-head	2m 38s
windows-latest 2.3	2m 40s
windows-latest 2.4	3m 34s
windows-latest 2.5	4m 32s
windows-latest 2.6	5m 26s
windows-latest 2.7	3m 30s
windows-latest 3.0	2m 12s
windows-latest 3.1	2m 15s
windows-latest 3.2	2m 11s
windows-latest head	1m 55s
ubuntu-latest jruby-9.1	2m 9s
ubuntu-latest jruby-9.2	1m 57s
ubuntu-latest jruby-9.3	1m 28s
	1h 55m 43s

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