I see you posed from Thunderbird, but do you use Evolution, at all?
Email, calendar, contacts? If so it'll be trying to log in to a
service, wanting its credentials.
Other things have come to use parts of evolution as their libraries.
For instance, if I try to remove evolution-data-server, it wants to
remove gnome-shell, gnome-contacts, and folks, as well.
If you look in gnome-session-properties (I'm doing this from old info,
it may have changed since then), you'll see applications that will be
started up when you log in. There could be something evolution related
in there that you aren't actually using.
I don't use Evolution, but like you said other things including GNOME
Calendar use evolution-data-server. I can make KeePassXC not prompt me
when a program tries to search, but I would have to remember to unlock
the database every time before doing anything that needs it. I don't
have any auto-started programs that might need Secret Service other than
Thunderbird, and last time I checked Thunderbird doesn't support Secret
Service.
Alex