Pass through nil as digest when signing certificates #1059

Job	Run time
openssl-1.0.2u	2m 24s
openssl-1.1.0l	1m 38s
openssl-1.1.1w	1m 44s
openssl-3.0.13	2m 50s
openssl-3.1.5	2m 55s
openssl-3.2.1	3m 12s
openssl-3.3.0	3m 35s
libressl-3.1.5	2m 9s
libressl-3.2.7	2m 15s
libressl-3.3.6	2m 31s
libressl-3.4.3	2m 31s
libressl-3.5.3	2m 22s
libressl-3.6.3	3m 9s
libressl-3.7.3	2m 15s
libressl-3.8.4	2m 13s
libressl-3.9.1	2m 25s
openssl-3.0.13 fips	3m 7s
openssl-3.1.5 fips	2m 45s
openssl-3.2.1 fips	3m 17s
openssl-3.3.0 fips	3m 15s
openssl-head	3m 21s
openssl-head fips	3m 30s
openssl-head no-legacy	3m 39s
ruby-versions / Generate Ruby versions	2s
ubuntu-22.04 2.7	1m 4s
ubuntu-22.04 3.0	56s
ubuntu-22.04 3.1	1m 2s
ubuntu-22.04 3.2	1m 3s
ubuntu-22.04 3.3	1m 1s
ubuntu-22.04 head	1m 11s
ubuntu-22.04 truffleruby	1m 39s
ubuntu-22.04 truffleruby-head	1m 56s
ubuntu-20.04 2.7	1m 1s
ubuntu-20.04 3.0	53s
ubuntu-20.04 3.1	1m 1s
ubuntu-20.04 3.2	57s
ubuntu-20.04 3.3	56s
ubuntu-20.04 head	57s
ubuntu-20.04 truffleruby-head	1m 58s
macos-latest 2.7	56s
macos-latest 3.0	54s
macos-latest 3.1	56s
macos-latest 3.2	48s
macos-latest 3.3	42s
macos-latest head	37s
macos-latest truffleruby-head	1m 8s
windows-latest 2.7	6m 5s
windows-latest 3.0	4m 20s
windows-latest 3.1	4m 29s
windows-latest 3.2	5m 36s
windows-latest 3.3	5m 44s
windows-latest head	4m 18s
windows-latest ucrt	3m 45s
windows-latest mswin	3m 4s
	2h 4m 1s

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