pkcs7: remove default cipher from PKCS7.encrypt #1166

Job	Run time
openssl-1.0.2u	51s
openssl-1.1.0l	57s
openssl-1.1.1w	52s
openssl-3.0.14	56s
openssl-3.1.6	58s
openssl-3.2.2	56s
openssl-3.3.1	57s
openssl-master	3m 35s
libressl-3.1.5	56s
libressl-3.2.7	1m 0s
libressl-3.3.6	1m 4s
libressl-3.4.3	1m 0s
libressl-3.5.3	1m 0s
libressl-3.6.3	57s
libressl-3.7.3	57s
libressl-3.8.4	56s
libressl-3.9.2	1m 2s
openssl-3.0.14 with fips provider	43s
openssl-3.1.6 with fips provider	43s
openssl-3.2.2 with fips provider	41s
openssl-3.3.1 with fips provider	45s
openssl-master with fips provider	3m 24s
openssl-3.3.1 without legacy provider	53s
ruby-versions / Generate Ruby versions	4s
ubuntu-22.04 2.7	54s
ubuntu-22.04 3.0	52s
ubuntu-22.04 3.1	1m 1s
ubuntu-22.04 3.2	58s
ubuntu-22.04 3.3	58s
ubuntu-22.04 head	1m 1s
ubuntu-22.04 truffleruby	1m 34s
ubuntu-22.04 truffleruby-head	1m 40s
ubuntu-20.04 2.7	1m 0s
ubuntu-20.04 3.0	1m 0s
ubuntu-20.04 3.1	1m 1s
ubuntu-20.04 3.2	1m 1s
ubuntu-20.04 3.3	55s
ubuntu-20.04 head	54s
ubuntu-20.04 truffleruby	1m 38s
ubuntu-20.04 truffleruby-head	1m 33s
macos-latest 2.7	1m 2s
macos-latest 3.0	35s
macos-latest 3.1	48s
macos-latest 3.2	51s
macos-latest 3.3	38s
macos-latest head	37s
macos-latest truffleruby	56s
macos-latest truffleruby-head	57s
windows-latest 2.7	5m 43s
windows-latest 3.0	3m 59s
windows-latest 3.1	3m 56s
windows-latest 3.2	3m 46s
windows-latest 3.3	6m 21s
windows-latest head	3m 46s
windows-latest ucrt	3m 47s
windows-latest mswin	2m 51s
	1h 24m 40s

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