Podman 6.0 released: moves to Netavark/Pasta/nftables, Quadlet gains a REST API

Podman 6.0 is a major release focused on modernizing the networking stack and improving the Quadlet and podman machine experience.

Key points

• Networking: transitions from slirp4netns and iptables toward Netavark, Pasta and nftables; adds experimental Pasta rootless port-forwarding that preserves the correct source IP for rootless containers on custom networks.
• Podman Machine: a smoother multi-provider experience across different VM providers, plus a new podman machine os update command to keep VM environments current.
• Quadlet: adds REST API support, better tracking of associated files, expanded features for .volume units, and additional search paths for packaging.
• Configuration: updated config-file handling for a more reliable experience in multi-user environments.
• Docker compatibility: updated Docker API support and refined command output.