folders containing dot not synced

[juju4]

Follow-up of OfflineIMAP/offlineimap#629 or OfflineIMAP/offlineimap#693

Same issue with offlineimap 8.0.0 on Fedora41 (offlineimap-8.0.0-14.fc41 - offlineimap v8.0.0, imaplib2 v3.06, Python v3.13.1, OpenSSL 3.2.2 4 Jun 2024). Folder is created but no content.
Possibly because '.' being use as replacement character (f/attachments because f.attachments)
No separator defined in offlineimaprc. Adding "sep = /" on gmail-remote side does not help.
From debug logs, those folders only appear at maildir scan but never in message list/syncing part.

2025-01-16 20:37:15 DEBUG: [maildir]:   dirname = personal.2024
2025-01-16 20:37:15 DEBUG: [maildir]:   This is maildir folder 'personal.2024'.
[...]
2025-01-16 20:37:15 DEBUG: [maildir]: _GETFOLDERS_SCANDIR RETURNING ['personal.2024', ...]
[...]
2025-01-16 20:39:14 DEBUG: Message list for Gmail[personal] loaded: N messages
2025-01-16 20:39:14 DEBUG: Syncing messages Gmail[personal] -> GmailMaildir[personal]
2025-01-16 20:39:14 DEBUG: []: Not syncing to read-only repository 'gmail-remote

This function lists all folders
https://github.com/OfflineIMAP/offlineimap3/blob/master/offlineimap/repository/Maildir.py#L169
Function not called for folders containing a dot
https://github.com/OfflineIMAP/offlineimap3/blob/master/offlineimap/ui/UIBase.py#L379 loadmessagelist()
https://github.com/OfflineIMAP/offlineimap3/blob/master/offlineimap/ui/UIBase.py#L384 messagelistloaded()
called here
https://github.com/OfflineIMAP/offlineimap3/blob/master/offlineimap/folder/IMAP.py#L284 in cachemessagelist() start
https://github.com/OfflineIMAP/offlineimap3/blob/master/offlineimap/folder/IMAP.py#L330 in cachemessagelist() end
not sure how far should go.

The accounts.py __sync ignored folders (https://github.com/OfflineIMAP/offlineimap3/blob/master/offlineimap/accounts.py#L332) and logs match what I expect and does not include unrequested folders with dot.

Tested a folder with name "test-2024" and sync correctly.
Tested a folder with name "test/2025" and sync correctly (as "test.2025").
Note that gmail does not allow to create "test/2024" after creating "test-2024".