Require podman

This is prep for supporting bootc:
#5197

A big part of the idea with bootc is that with `bootc install`,
a container image can *install itself*:
https://github.com/containers/bootc/blob/main/docs/install.md

This will longer term replace the `ostreecontainer` verb.

However even beyond that, having podman on the (smaller netinst,
as well as bigger DVD) installer ISO will just generally be
useful for a variety of things.  For example,
one can now do e.g.:

```
%post --no-chroot
podman run ...
```

Which unblocks a lot of things!  (Some of which admittedly will
be hacks, but that's what a lot of `%post` is...)

Having a container runtime in the Live ISO is a very key
feature of the Fedora CoreOS (and RHEL CoreOS) Live ISOs,
and this brings Anaconda closer to parity too.

anaconda.spec.in

@@ -104,6 +104,8 @@ Requires: python3-pwquality
 Requires: python3-systemd
 Requires: python3-productmd
 Requires: python3-dasbus >= %{dasbusver}
+# Needed for bootc
+Requires: podman
 Requires: flatpak-libs
 %if %{defined rhel} && %{undefined centos}
 Requires: subscription-manager >= %{subscriptionmanagerver}