feat(isync): don't expire unread email

GitOrigin-RevId: 846c1799a02226df58c10d7687b3df70c3dca39b
diff --git a/private_dot_config/isyncrc.tmpl b/private_dot_config/isyncrc.tmpl
index ab77aec..19d083b 100644
--- a/private_dot_config/isyncrc.tmpl
+++ b/private_dot_config/isyncrc.tmpl
@@ -3,6 +3,8 @@
 # Heavily inspired by:
 # https://wiki.archlinux.org/index.php?title=Isync&oldid=823186#Configuring.
 
+ExpireUnread no
+
 IMAPAccount gmail
 Host imap.gmail.com
 # The User and PassCmd fields are not available in dotfiles-external, only in