Reduce OpenSSL::Buffering#do_write overhead #1300

Job	Run time
openssl-1.0.2u	55s
openssl-1.1.0l	53s
openssl-1.1.1w	1m 1s
openssl-3.0.15	57s
openssl-3.1.7	56s
openssl-3.2.3	57s
openssl-3.3.2	58s
openssl-3.4.0	1m 0s
openssl-master	3m 52s
libressl-3.1.5	54s
libressl-3.2.7	1m 1s
libressl-3.3.6	1m 6s
libressl-3.4.3	59s
libressl-3.5.3	1m 6s
libressl-3.6.3	58s
libressl-3.7.3	1m 2s
libressl-3.8.4	58s
libressl-3.9.2	57s
libressl-4.0.0	54s
openssl-3.0.15 with fips provider	52s
openssl-3.1.7 with fips provider	51s
openssl-3.2.3 with fips provider	52s
openssl-3.3.2 with fips provider	50s
openssl-3.4.0 with fips provider	50s
openssl-master with fips provider	3m 44s
openssl-3.4.0 without legacy provider	57s
ruby-versions / Generate Ruby versions	1s
ubuntu-22.04 2.7	40s
ubuntu-22.04 3.0	52s
ubuntu-22.04 3.1	59s
ubuntu-22.04 3.2	57s
ubuntu-22.04 3.3	1m 4s
ubuntu-22.04 3.4	1m 3s
ubuntu-22.04 head	1m 5s
ubuntu-22.04 truffleruby	1m 35s
ubuntu-22.04 truffleruby-head	1m 45s
ubuntu-20.04 2.7	36s
ubuntu-20.04 3.0	1m 6s
ubuntu-20.04 3.1	54s
ubuntu-20.04 3.2	1m 7s
ubuntu-20.04 3.3	54s
ubuntu-20.04 3.4	54s
ubuntu-20.04 head	55s
ubuntu-20.04 truffleruby	1m 36s
ubuntu-20.04 truffleruby-head	1m 41s
macos-latest 2.7	35s
macos-latest 3.0	33s
macos-latest 3.1	35s
macos-latest 3.2	34s
macos-latest 3.3	39s
macos-latest 3.4	40s
macos-latest head	39s
macos-latest truffleruby	1m 0s
macos-latest truffleruby-head	1m 1s
windows-latest 2.7	3m 34s
windows-latest 3.0	3m 38s
windows-latest 3.1	4m 39s
windows-latest 3.2	4m 33s
windows-latest 3.3	5m 38s
windows-latest 3.4	9s
windows-latest head	5m 13s
windows-latest ucrt	3m 40s
windows-latest mswin	2m 25s
	1h 29m 49s

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