Append flags from environment variables. #723

Job	Run time
openssl-1.0.2u	2m 59s
openssl-1.1.0l	2m 9s
openssl-1.1.1t	2m 20s
openssl-3.0.8	4m 23s
libressl-3.1.5	3m 16s
libressl-3.2.7	3m 6s
libressl-3.3.6	2m 59s
libressl-3.4.3	2m 59s
libressl-3.5.3	3m 31s
libressl-3.6.1	3m 3s
libressl-3.7.0	3m 6s
openssl-3.0.8 fips	4m 23s
ruby-versions / Generate Ruby versions	2s
ubuntu-22.04 2.6	1m 10s
ubuntu-22.04 2.7	1m 24s
ubuntu-22.04 3.0	1m 2s
ubuntu-22.04 3.1	1m 12s
ubuntu-22.04 3.2	1m 7s
ubuntu-22.04 head	1m 23s
ubuntu-22.04 truffleruby	2m 1s
ubuntu-22.04 truffleruby-head	1m 49s
ubuntu-20.04 2.6	1m 16s
ubuntu-20.04 2.7	1m 10s
ubuntu-20.04 3.0	1m 5s
ubuntu-20.04 3.1	1m 7s
ubuntu-20.04 3.2	1m 6s
ubuntu-20.04 head	1m 13s
ubuntu-20.04 truffleruby-head	1m 54s
macos-latest 2.6	2m 25s
macos-latest 2.7	2m 12s
macos-latest 3.0	1m 33s
macos-latest 3.1	1m 22s
macos-latest 3.2	1m 36s
macos-latest head	1m 32s
macos-latest truffleruby-head	4m 24s
windows-latest 2.6	6m 26s
windows-latest 2.7	5m 30s
windows-latest 3.0	6m 19s
windows-latest 3.1	4m 53s
windows-latest 3.2	5m 2s
windows-latest ucrt	5m 9s
windows-latest mswin	5m 29s
	1h 52m 7s

Provide feedback