Firewall policy setup error with port forwarding in `firewalld` mode

# Description

On RockyLinux 9, trying to start a rootful container with port forwarding while using the `firewalld` firewall driver causes the startup to fail.

```sh
# NETAVARK_FW=firewalld podman run --rm -p=8000:80/tcp docker.io/httpd:latest
Error: netavark: Failed to update firewalld policy netavark_portfwd port forwarding rules: DBus error: org.fedoraproject.FirewallD1.Exception: INVALID_FORWARD: Policy 'netavark_portfwd': A 'forward-port' with 'to-addr' is invalid for egress zone 'HOST'
```

# Steps to reproduce

1. Prepare a RockyLinux 9 machine (I've tested both x86_64 and aarch64; doesn't seem to matter).
2. Install `firewalld` and `podman` from repository: `dnf install -y firewalld podman`.
3. Make sure `firewalld.service` is running: `systemctl start firewalld.service`.
4. Try to start a container with `firewalld` as firewall driver and observe the error.

# Versions

kernel: `5.14.0-611.9.1.el9_7.aarch64`
podman: `6:5.6.0-7.el9_7`
netavark: `2:1.16.0-1.el9`
firewalld: `1.3.4-15.el9_6`

# Additional notes

Interestingly, this issue does not happen on ArchLinux with podman 5.7.0, netavark 1.17.0, and firewalld 2.4.0. I self-compiled netavark 1.17.0 (with aardvark-dns 1.17.0) on RockyLinux 9 and retried, but got the same results. So it seems to me that the most likely explanation is that the firewalld policy syntax used to be stricter, but has since been relaxed some time between 1.3.4 and 2.4.0.