KTailctl v0.20.2

No user-facing changes, includes dependency updates and some minor internal changes

Features & Enhancements

• Add action to update nix flake

Fixes

• Do not use SSH for flathub submodule, thanks @renner0e
• Hotfix github.com/gorilla/csrf (transient dependency) (CVE-2025-24358)

Chores

Flatpak:

• Update KDE runtime/SDK: 6.8 -> 6.9

Go:

• Update tailscale.com: v1.82.5 -> 1.84.1
• Update golang.org/x/net: v0.39.0 -> v0.40.0