Not possible. Access templates are only for entity level access. For space and dB acces, it’s reconfigured templates.
You can vote for this though: Access templates at the database level
A workaround would be to have an automation to assign a user group to all entities on creation, then assign “automatically share with user group” based on that field, with an access template where they can’t delete.
Then also make them submitters to that database.
Theres one more workaround to avoid deleting, and that’s to add a relation and a set the other side of it to required. So for example. Project → Tasks. If project is a required field in the task dB, you are not able to delete a project that has linked tasks. You could utalise this behavior somehow to prevent delete. Never tried it before though.