Add SSL_CTX_dup #78

Job	Run time
basic_clang	1m 13s
basic_gcc	1m 0s
check_docs	56s
check_update	1m 10s
check-ansi	55s
minimal	42s
self-hosted (freebsd-13.2)	1s
self-hosted (ubuntu-arm64-22.04)	1s
address_ub_sanitizer	9m 47s
enable_non-default_options	53s
external-test-cf-quiche	1m 29s
external-test-pyca (1.51.0, 3.9)	1m 9s
external-tests	1m 37s
full_featured	1m 6s
fuzz_tests	2m 54s
legacy	1m 2s
memory_sanitizer	18m 12s
no-deprecated	57s
no-legacy	1m 1s
non-caching	13m 9s
no-shared-macos	1m 51s
no-shared-ubuntu	1m 2s
out-of-readonly-source-and-install-macos	1m 42s
out-of-readonly-source-and-install-ubuntu	1m 0s
threads_sanitizer	1m 16s
	1h 6m 5s

Provide feedback