iso: fix packages.x86_64 (no inline comments; gstreamer-vaapi -> gst-plugin-va)

Inline comments after a package name broke kitty/flatpak (became invalid
names with trailing whitespace). gstreamer-vaapi was removed from Arch.
calamares is AUR-only -> commented pending a [tanin] rebuild decision.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

iso/build-profile/airootfs/etc/systemd/network/20-ethernet.network

@@ -0,0 +1,22 @@
+[Match]
+Type=ether
+# Exclude virtual Ethernet interfaces
+Kind=!*
+
+[Link]
+RequiredForOnline=routable
+
+[Network]
+DHCP=yes
+MulticastDNS=yes
+
+# systemd-networkd does not set per-interface-type default route metrics
+# https://github.com/systemd/systemd/issues/17698
+# Explicitly set route metric, so that Ethernet is preferred over Wi-Fi and Wi-Fi is preferred over mobile broadband.
+# Use values from NetworkManager. From nm_device_get_route_metric_default in
+# https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/blob/main/src/core/devices/nm-device.c
+[DHCPv4]
+RouteMetric=100
+
+[IPv6AcceptRA]
+RouteMetric=100