Drop tests for shipped one-shot migrations (#10318)

Keep the migrations themselves for late-updaters. Drop the tests that only
exercised frozen file rewrites from 4.0.0, and keep live invariants,
privileged repairs, and the migrator.

test/shell.d/network-manager-transition-test.sh

@@ -6,7 +6,6 @@ source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/base-test.sh"
 
 dns="$ROOT/bin/omarchy-dns"
 hardware_network="$ROOT/install/hardware/network.sh"
-migration="$ROOT/migrations/1782002156.sh"
 
 ! grep -F 'systemd-networkd' "$dns" >/dev/null || fail "omarchy-dns no longer restarts systemd-networkd"
 grep -F 'NetworkManager/conf.d/20-omarchy-dns.conf' "$dns" >/dev/null
@@ -26,10 +25,3 @@ grep -F 'systemd-networkd.socket' "$hardware_network" >/dev/null
 grep -F '20-wlan.network' "$hardware_network" >/dev/null
 grep -F 'omarchy-networkd-retired' "$hardware_network" >/dev/null
 pass "hardware setup retires archinstall networkd state"
-
-grep -F 'OMARCHY_UPGRADE_TO_QUATTRO_LIVE' "$migration" >/dev/null
-grep -F 'systemctl disable --now "$unit"' "$migration" >/dev/null
-grep -F 'systemctl stop systemd-networkd.service' "$migration" >/dev/null
-grep -F 'NetworkManager.service' "$migration" >/dev/null
-grep -F '20-wlan.network' "$migration" >/dev/null
-pass "migration repairs upgraded systems with networkd still active"