perf: don't check for peer certificate chain APIs on CPython/PyPy

create_default_context() is quite slow on Linux as OpenSSL 3.x
verify location loading is painfully slow. I've observed ~15 ms per
call.

On CPython and PyPy, we can skip this check since we already know
the required APIs exist.

Author: ichard26

src/truststore/__init__.py

@@ -7,7 +7,7 @@
 
 # Detect Python runtimes which don't implement SSLObject.get_unverified_chain() API
 # This API only became public in Python 3.13 but was available in CPython and PyPy since 3.10.
-if _sys.version_info < (3, 13):
+if _sys.version_info < (3, 13) and _sys.implementation.name not in ("cpython", "pypy"):
     try:
         import ssl as _ssl
     except ImportError: