How to filter out resource mailboxes from Azure AD/Entra ID Dynamic Group?

Hi!
I'm creating a dynamic group in Azure that only contains our active employee accounts. I figured I should use the "city" attribute because we don't use that for our service accounts, guest users, or admin accounts.
I created a dynamic group with the following rule:
user.accountEnabled -eq True and user.city -in ["value1". "value2", "value3"]
The problem is that this query also includes our room and device mailboxes because they have the city info filled out in Exchange Admin Center.
How can I filter these room and device mailboxes out of this dynamic group? I tried to filter based on the assigned license, but validation always ended up failing because of an invalid syntax rule.