Minor bugfixes (#7891)

* Fix dangerous default argument

* Remove unused imports

* Remove unnecessary comprehension

* Use literal syntax to create data structure

* Use literal syntax instead of function calls to create data structure

Co-authored-by: deepsource-autofix[bot] <62050782+deepsource-autofix[bot]@users.noreply.github.com>

certbot-ci/certbot_integration_tests/certbot_tests/context.py

@@ -1,5 +1,4 @@
 """Module to handle the context of integration tests."""
-import logging
 import os
 import shutil
 import sys

certbot-ci/certbot_integration_tests/utils/misc.py

@@ -236,7 +236,7 @@ def generate_csr(domains, key_path, csr_path, key_type=RSA_KEY_TYPE):
         file_h.write(crypto.dump_privatekey(crypto.FILETYPE_PEM, key))
 
     req = crypto.X509Req()
-    san = ', '.join(['DNS:{0}'.format(item) for item in domains])
+    san = ', '.join('DNS:{0}'.format(item) for item in domains)
     san_constraint = crypto.X509Extension(b'subjectAltName', False, san.encode('utf-8'))
     req.add_extensions([san_constraint])