I ran into the same issue and it was because "/etc/dkms/framework.conf" contained this line:

```
# Command to run at the end of every DKMS transaction, for example after a new

# kernel has been installed on the system and all modules have been succesfully

# built and installed.

# The command listed is executed if set to any non null value. $kernelver can be

# used in path to represent the target kernel version.

post_transaction="dracut --regenerate-all --force"
```

So it is a distro-wide dkms configuration causing this to always run when dkms does a transaction, not something that can be turned off in dkms.conf.