ssl module cannot wrap sockets before connecting after inject_into_ssl()

[roelandschoukens]

truststore.inject_into_ssl() will break sslcontext.wrap_socket():

import ssl
import socket

import truststore
truststore.inject_into_ssl()

sslcontext = ssl.create_default_context()
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s = sslcontext.wrap_socket(s, server_hostname="example.com")

causing it to fail with

  File "test.py", line 9, in <module>
    s = sslcontext.wrap_socket(s, server_hostname="example.com")
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\******\Python312\site-packages\truststore\_api.py", line 130, in wrap_socket
    _verify_peercerts(ssl_sock, server_hostname=server_hostname)
  File "C:\******\Python312\site-packages\truststore\_api.py", line 338, in _verify_peercerts
    cert_bytes = _get_unverified_chain_bytes(sslobj)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\******\Python312\site-packages\truststore\_api.py", line 320, in _get_unverified_chain_bytes
    unverified_chain = sslobj.get_unverified_chain() or ()  # type: ignore[attr-defined]
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'get_unverified_chain'

Internally, in truststore/_api.py in _verify_peercerts(), the sock_or_sslobj parameter is an object with a _sslobj field, but that field is set to None. Note that the socket is not yet connected, and the documentation of the ssl module states:

For client-side sockets, the context construction is lazy; if the underlying socket isn’t connected yet, the context construction will be performed after connect() is called on the socket.

implying that the _sslobj field will be set only when calling connect().