After hours of troubleshooting i managed to manually install the taas plugin in my packstack stein environment, this is how i did in case someone else would find themselves having the same issue.

Download the RPM

wget https://cbs.centos.org/kojifiles/pack...

Install the package

yum -y install python2-tap-as-a-service-5.0.0-1.el7.noarch.rpm

Then make sure taas in added to service_plugins in /etc/neutron/neutron.conf

service_plugins=qos,trunk,ovn-router,taas

And add the following to the same file

[service_providers]

service_provider = TAAS:TAAS:neutron_taas.services.taas.service_drivers.taas_rpc.TaasRpcDriver:default

[taas]

driver = neutron_taas.services.taas.drivers.linux.ovs_taas.OvsTaasDriver

enabled = True

Then update the database

neutron-db-manage upgrade heads

Lastly, restart neutron

systemctl restart neutron-server