firewalld conflicts with nftables

[Benjamin Hackl-Blaimschein]

firewalld should not be started when nftables is active:

systemd.service must conflict with nftables.service

This bug was already fixed in RHEL some time ago, for reference see:
https://bugzilla.redhat.com/show_bug.cgi?id=1817205

How to reproduce this bug:

1) install and start nftables
2) add some rules
3) install and start firewalld

The nft rules are now gone.

# lsb_release -rd
Description: Ubuntu 22.04.1 LTS
Release: 22.04

## Probably all versions of ubuntu affected

# apt-cache policy firewalld
firewalld:
  Installed: 1.1.1-1ubuntu1
  Candidate: 1.1.1-1ubuntu1

[Benjamin Hackl-Blaimschein (hacklbl)]

Sorry: should be:

firewalld.service must conflict with nftables.service