podman: drop slirp4netns which has been replaced by passt

see https://wiki.alpinelinux.org/wiki/Release_Notes_for_Alpine_3.20.0#podman_5.x

pkgs/applications/virtualization/podman/default.nix

@@ -23,7 +23,6 @@
 , runc
 , conmon
 , extraRuntimes ? lib.optionals stdenv.isLinux [ runc ] # e.g.: runc, gvisor, youki
-, slirp4netns
 , fuse-overlayfs
 , util-linux
 , iptables
@@ -56,7 +55,6 @@ let
  aardvark-dns
  catatonit # added here for the pause image and also set in `containersConf` for `init_path`
  netavark
- slirp4netns
  passt
  conmon
  crun