``unselect_folder()`` causes ``IllegalStateError``

[lumpi101]

I get an IllegalStateError when executing enable(...) after unselect_folder(). It seems to me that unselect_folder() does not update the state imaplib.IMAP4.state from "SELECTED" to "AUTH" (imaplib.IMAP4.unselect does this but imapclient.IMAPClient.unselect_folder not).
close_folder() works without problems.

Versions:
Python 3.13
imapclient 3.1.0

Code to reproduce:

import os
from imapclient import IMAPClient

with IMAPClient(os.environ["EMAIL_IMAP_SERVER"]) as imap:
    imap.login(os.environ["EMAIL_ADDRESS"], os.environ["EMAIL_PASSWORD"])
    imap.select_folder("INBOX")
    imap.unselect_folder()
    imap.enable("UTF8=ACCEPT")

Error:

---------------------------------------------------------------------------
IllegalStateError                         Traceback (most recent call last)
Cell In[30], [line 8](vscode-notebook-cell:?execution_count=30&line=8)
      4 with IMAPClient(os.environ["EMAIL_IMAP_SERVER"]) as imap:
      5     imap.login(os.environ["EMAIL_ADDRESS"], os.environ["EMAIL_PASSWORD"])
      6     imap.select_folder("INBOX")
      7     imap.unselect_folder()
----> [8]     imap.enable("UTF8=ACCEPT")

File xxx/lib/python3.13/site-packages/imapclient/imapclient.py:179, in require_capability.<locals>.actual_decorator.<locals>.wrapper(client, *args, **kwargs)
    175 if not client.has_capability(capability):
    176     raise exceptions.CapabilityError(
    177         "Server does not support {} capability".format(capability)
    178     )
--> [179] return func(client, *args, **kwargs)

File xxx/lib/python3.13/site-packages/imapclient/imapclient.py:554, in IMAPClient.enable(self, *capabilities)
    538 """Activate one or more server side capability extensions.
    539 
    540 Most capabilities do not need to be enabled. This is only
   (...)    551 See :rfc:`5161` for more details.
    552 """
    553 if self._imap.state != "AUTH":
--> [554]     raise exceptions.IllegalStateError(
    555         "ENABLE command illegal in state %s" % self._imap.state
    556     )
    558 resp = self._raw_command_untagged(
    559     b"ENABLE",
    560     [to_bytes(c) for c in capabilities],
   (...)    563     unpack=True,
    564 )
    565 if not resp:

IllegalStateError: ENABLE command illegal in state SELECTED