Add X509::Certificate#tbs_bytes #1067

Job	Run time
openssl-1.0.2u	2m 35s
openssl-1.1.0l	1m 29s
openssl-1.1.1w	1m 45s
openssl-3.0.13	2m 51s
openssl-3.1.5	2m 50s
openssl-3.2.1	3m 30s
openssl-3.3.0	3m 19s
libressl-3.1.5	2m 7s
libressl-3.2.7	2m 24s
libressl-3.3.6	2m 12s
libressl-3.4.3	2m 13s
libressl-3.5.3	2m 17s
libressl-3.6.3	2m 15s
libressl-3.7.3	2m 32s
libressl-3.8.4	2m 12s
libressl-3.9.1	2m 9s
openssl-3.0.13 fips	2m 41s
openssl-3.1.5 fips	2m 46s
openssl-3.2.1 fips	3m 5s
openssl-3.3.0 fips	3m 12s
openssl-head	3m 19s
openssl-head fips	3m 25s
openssl-head no-legacy	3m 22s
ruby-versions / Generate Ruby versions	2s
ubuntu-22.04 2.7	1m 1s
ubuntu-22.04 3.0	57s
ubuntu-22.04 3.1	1m 2s
ubuntu-22.04 3.2	1m 19s
ubuntu-22.04 3.3	55s
ubuntu-22.04 head	55s
ubuntu-22.04 truffleruby	1m 43s
ubuntu-22.04 truffleruby-head	1m 44s
ubuntu-20.04 2.7	54s
ubuntu-20.04 3.0	56s
ubuntu-20.04 3.1	55s
ubuntu-20.04 3.2	50s
ubuntu-20.04 3.3	51s
ubuntu-20.04 head	51s
ubuntu-20.04 truffleruby-head	1m 44s
macos-latest 2.7	49s
macos-latest 3.0	37s
macos-latest 3.1	47s
macos-latest 3.2	38s
macos-latest 3.3	38s
macos-latest head	41s
macos-latest truffleruby-head	1m 25s
windows-latest 2.7	4m 39s
windows-latest 3.0	3m 41s
windows-latest 3.1	3m 55s
windows-latest 3.2	4m 0s
windows-latest 3.3	4m 9s
windows-latest head	3m 43s
windows-latest ucrt	3m 30s
windows-latest mswin	2m 45s
	1h 53m 6s

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