You can execute the command
Add-migration temporary
to create a new empty migration. Then, run
Remove-Migration temporary (or their dotnet-cli counterparts)
In recent editions of EF Core (3+), just use:
Remove-Migration (will revert the last migration)
It will create model snapshot from scratch even if the migration has already been deleted. This approach works perfectly for Ef core 2.2.0-rtm-35687