Add X509::Certificate#tbs_bytes #1051

Job	Run time
openssl-1.0.2u	2m 31s
openssl-1.1.0l	1m 31s
openssl-1.1.1w	1m 41s
openssl-3.0.13	2m 49s
openssl-3.1.5	2m 52s
openssl-3.2.1	3m 12s
ruby-versions / Generate Ruby versions	2s
openssl-3.3.0	3m 27s
libressl-3.1.5	2m 3s
libressl-3.2.7	2m 15s
libressl-3.3.6	2m 14s
libressl-3.4.3	2m 18s
libressl-3.5.3	2m 17s
libressl-3.6.3	2m 28s
libressl-3.7.3	2m 18s
libressl-3.8.4	2m 23s
libressl-3.9.1	2m 16s
openssl-3.0.13 fips	2m 54s
openssl-3.1.5 fips	2m 52s
openssl-3.2.1 fips	3m 15s
openssl-3.3.0 fips	3m 16s
openssl-head	3m 38s
openssl-head fips	3m 30s
openssl-head no-legacy	3m 30s
ubuntu-22.04 2.7	58s
ubuntu-22.04 3.0	53s
ubuntu-22.04 3.1	58s
ubuntu-22.04 3.2	1m 0s
ubuntu-22.04 3.3	56s
ubuntu-22.04 head	56s
ubuntu-22.04 truffleruby	1m 23s
ubuntu-22.04 truffleruby-head	1m 30s
ubuntu-20.04 2.7	55s
ubuntu-20.04 3.0	50s
ubuntu-20.04 3.1	52s
ubuntu-20.04 3.2	55s
ubuntu-20.04 3.3	50s
ubuntu-20.04 head	50s
ubuntu-20.04 truffleruby-head	1m 28s
macos-latest 2.7	48s
macos-latest 3.0	43s
macos-latest 3.1	40s
macos-latest 3.2	40s
macos-latest 3.3	37s
macos-latest head	38s
macos-latest truffleruby-head	1m 3s
windows-latest 2.7	4m 44s
windows-latest 3.0	1m 29s
windows-latest 3.1	1m 47s
windows-latest 3.2	1m 53s
windows-latest 3.3	4m 52s
windows-latest ucrt	4m 0s
windows-latest mswin	2m 30s
	1h 43m 10s

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