Optimize openssl memory leak test

Just do one call and check whether memory usage changes. Looping
this 100000 times is extremely slow with debug builds of openssl.

Migrate SKIPIF -> EXTENSIONS (#7138)

This is an automated migration of most SKIPIF extension_loaded checks.

Convert resources to objects in ext/openssl

Closes GH-5860

Co-authored-by: Nikita Popov <nikita.ppv@gmail.com>

Fix #79145: openssl memory leak

We must increase the refcount of `return_value` only if `cert` is a
resource; this is already done in `php_openssl_evp_from_zval()`,
though.