Remove references to "19" methods in JRuby #248

Job	Run time
ruby-versions / Generate Ruby versions	4s
ubuntu-20.04 2.3	55s
ubuntu-20.04 2.4	52s
ubuntu-20.04 2.5	58s
ubuntu-20.04 2.6	1m 0s
ubuntu-20.04 2.7	56s
ubuntu-20.04 3.0	24s
ubuntu-20.04 3.1	23s
ubuntu-20.04 3.2	19s
ubuntu-20.04 3.3	23s
ubuntu-20.04 head	21s
ubuntu-20.04 jruby	1m 8s
ubuntu-20.04 jruby-head	1m 8s
ubuntu-22.04 2.3	1m 0s
ubuntu-22.04 2.4	54s
ubuntu-22.04 2.5	54s
ubuntu-22.04 2.6	56s
ubuntu-22.04 2.7	57s
ubuntu-22.04 3.0	21s
ubuntu-22.04 3.1	22s
ubuntu-22.04 3.2	17s
ubuntu-22.04 3.3	23s
ubuntu-22.04 head	21s
ubuntu-22.04 jruby	1m 1s
ubuntu-22.04 jruby-head	1m 13s
macos-12 2.3	1m 58s
macos-12 2.4	2m 6s
macos-12 2.5	2m 29s
macos-12 2.6	2m 30s
macos-12 2.7	2m 16s
macos-12 3.0	24s
macos-12 3.1	26s
macos-12 3.2	24s
macos-12 3.3	50s
macos-12 head	26s
macos-12 jruby	59s
macos-12 jruby-head	2m 31s
macos-13 2.3	2m 6s
macos-13 2.4	3m 28s
macos-13 2.5	1m 56s
macos-13 2.6	3m 8s
macos-13 2.7	2m 35s
macos-13 3.0	38s
macos-13 3.1	26s
macos-13 3.2	25s
macos-13 3.3	40s
macos-13 head	31s
macos-13 jruby	1m 10s
macos-13 jruby-head	1m 12s
macos-14 2.6	1m 2s
macos-14 2.7	55s
macos-14 3.0	18s
macos-14 3.1	19s
macos-14 3.2	17s
macos-14 3.3	18s
macos-14 head	17s
macos-14 jruby	43s
macos-14 jruby-head	42s
windows-latest 2.3	2m 13s
windows-latest 2.4	2m 16s
windows-latest 2.5	3m 45s
windows-latest 2.6	3m 6s
windows-latest 2.7	3m 43s
windows-latest 3.0	1m 10s
windows-latest 3.1	1m 31s
windows-latest 3.2	2m 23s
windows-latest 3.3	2m 36s
windows-latest head	1m 39s
windows-latest mswin	1m 45s
ubuntu-latest jruby-9.1	1m 21s
ubuntu-latest jruby-9.2	1m 19s
ubuntu-latest jruby-9.3	1m 5s
ubuntu-latest jruby-9.4	1m 22s
	1h 29m 9s

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