tests: drop distutils

distutils is going away in python 3.12.  LooseVersion() wasn't really
being used for anything particularly useful.  The strings that were
returned by the openssl backend for the cryptography module, or the
GPGME "engine" version were both just being replayed later as strings
anyway.

So, keep them in string form.  If future work needs to do things like
compare them, apparently packaging.version contains classes that might
be better-maintained going forward.

Signed-off-by: Daniel Kahn Gillmor <dkg@fifthhorseman.net>

tests/conftest.py

@@ -9,16 +9,11 @@ except ImportError:
 import os
 import sys
 
-from distutils.version import LooseVersion
-
 from cryptography.hazmat.backends import openssl
 
-openssl_ver = LooseVersion(openssl.backend.openssl_version_text().split(' ')[1])
-gpg_ver = LooseVersion('0')
+openssl_ver = openssl.backend.openssl_version_text().split(' ')[1]
+gpg_ver = 'unknown'
 gnupghome = os.path.join(os.path.dirname(__file__), 'gnupghome')
-if gpg:
-    gpgme_ver = gpg.core.check_version()
-
 
 # ensure external commands we need to run exist
 
@@ -52,7 +47,7 @@ def pytest_configure(config):
             os.unlink(fpath)
 
         # get the GnuPG version
-        gpg_ver.parse(gpg.core.get_engine_info()[0].version)
+        gpg_ver = list(filter(lambda x: x.protocol == gpg.constants.PROTOCOL_OpenPGP, gpg.core.get_engine_info()))[0].version
 
         # check that there are no keys loaded, now
         with gpg.Context(offline=True) as c: