Remove openssl dynlock functions
OpenSSL lets you provide hooks so that locks can be dynamically allocated. But it doesn't actually use those hooks: They don't appear in our unit test coverage, and the openssl manual even says:
Also, dynamic locks are currently not used internally by OpenSSL, but may do so in the future.
I propose that we disable this code. I'll do it as part of my #16794 (moved) branch.