pylint: upgrade pinned verson and fix new lints (#8936)

While bumping pinned packages in #8928, we came across a new version of pylint (2.9.3). Upgrading to this version requires some changes to Certbot's code, which is what this change is about.

* pylint: upgrade pinned verson and fix new lints

* maxsplit should be 1, not -1, for rsplit

certbot-apache/certbot_apache/_internal/override_centos.py

@@ -177,8 +177,8 @@ class CentOSParser(parser.ApacheParser):
     def parse_sysconfig_var(self):
         """ Parses Apache CLI options from CentOS configuration file """
         defines = apache_util.parse_define_file(self.sysconfig_filep, "OPTIONS")
-        for k in defines:
-            self.variables[k] = defines[k]
+        for k, v in defines.items():
+            self.variables[k] = v
 
     def not_modssl_ifmodule(self, path):
         """Checks if the provided Augeas path has argument !mod_ssl"""

certbot-apache/certbot_apache/_internal/override_fedora.py

@@ -87,5 +87,5 @@ class FedoraParser(parser.ApacheParser):
     def _parse_sysconfig_var(self):
         """ Parses Apache CLI options from Fedora configuration file """
         defines = apache_util.parse_define_file(self.sysconfig_filep, "OPTIONS")
-        for k in defines:
-            self.variables[k] = defines[k]
+        for k, v in defines.items():
+            self.variables[k] = v

certbot-apache/certbot_apache/_internal/override_gentoo.py

@@ -53,8 +53,8 @@ class GentooParser(parser.ApacheParser):
         """ Parses Apache CLI options from Gentoo configuration file """
         defines = apache_util.parse_define_file(self.apacheconfig_filep,
                                                 "APACHE2_OPTS")
-        for k in defines:
-            self.variables[k] = defines[k]
+        for k, v in defines.items():
+            self.variables[k] = v
 
     def update_modules(self):
         """Get loaded modules from httpd process, and add them to DOM"""