[3.12] gh-117310: Remove extra DECREF on "no ciphers" error path in `_ssl._SSLContext` constructor (GH-117309) (GH-117317)

gh-117310: Remove extra DECREF on "no ciphers" error path in `_ssl._SSLContext` constructor (GH-117309)

Remove extra self DECREF on ssl "no ciphers" error path.

This doesn't come up in practice because nobody links against a broken
OpenSSL library that provides nothing.
(cherry picked from commit 8cb7d7ff86a1a2d41195f01ba4f218941dd7308c)

Co-authored-by: Gregory P. Smith <greg@krypto.org>