package "iptables" has been replaced by "iptables-nft" on EL9

package "iptables" has been replaced by "iptables-nft" on EL9

There are some pointers given by dnf about "iptables", but these confuse
Puppet into aborting with the error message:

```console
Error: /Stage[main]/Firewall::Linux/Package[iptables]: Could not evaluate: no implicit conversion of Array into Hash
```

Fedora had a similar patch in commit 486e4b5779f5069e which I think
fixed the bug https://tickets.puppetlabs.com/browse/MODULES-11147 but
the same issue rared its head here on AlmaLinux 9.0.

The RPM for iptables-legacy states:

> This package contains the legacy tools which are obsoleted by
> nft-variants in iptables-nft package for backwards compatibility reasons.
> If you need to set up firewalls and/or IP masquerading, you should not install
> this package but either nftables or iptables-nft instead.