remove become_plugins ref from backported fix

changelogs/fragments/no_become_plugins.yml

@@ -0,0 +1,2 @@
+bugfixes:
+    - remove become plugins reference introduced in backport fix

lib/ansible/plugins/connection/persistent.py

@@ -37,7 +37,7 @@ import sys
 import termios
 
 from ansible import constants as C
-from ansible.plugins.loader import become_loader, cliconf_loader, connection_loader, httpapi_loader, netconf_loader, terminal_loader
+from ansible.plugins.loader import cliconf_loader, connection_loader, httpapi_loader, netconf_loader, terminal_loader
 from ansible.plugins.connection import ConnectionBase
 from ansible.module_utils._text import to_text
 from ansible.module_utils.connection import Connection as SocketConnection, write_to_file_descriptor
@@ -96,7 +96,6 @@ class Connection(ConnectionBase):
 
         env = os.environ.copy()
         env.update({
-                   'ANSIBLE_BECOME_PLUGINS': become_loader.print_paths(),
                    'ANSIBLE_CLICONF_PLUGINS': cliconf_loader.print_paths(),
                    'ANSIBLE_CONNECTION_PLUGINS': connection_loader.print_paths(),
                    'ANSIBLE_HTTPAPI_PLUGINS': httpapi_loader.print_paths(),