Although email is a required field (and everyone has at least one nowadays!), if you absolutely don't need to use it (something that we don't recommend because without it your users would not be able to do basic things such as recovering their passwords) there is a trick for you!
Create a single email address in Gmail and then use a feature that Gmail offers that lets you have near unlimited different aliases of your email addresses.
The trick is to add the plus character(+) right before the @ sign, followed by something unique.
For example if your email address is email@example.com, you can use firstname.lastname@example.org, email@example.com and so on. All those addresses would be valid in TalentLMS but any email sent to those addresses would reach the original account firstname.lastname@example.org.
This can be handy for example when mass importing your users.
Then you can disable any notifications that are scheduled for users since they won't be needed.