nwfilter/220-no-ip-spoofing.t: Update for newer guest distro

Commit 7a332e94 bumped the guest image from Fedora 38 to 40 and
roughly since then our integration tests started failing.  The test
which check that denying IP spoofing works counts with the fact that IP
address for the interface is updated using dhclient, but that is no
longer the case.  So instead of killing dhclient use nmcli to set the IP
address and restore it properly.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>

scripts/nwfilter/220-no-ip-spoofing.t

@@ -100,16 +100,12 @@ my $cmdfile = <<EOF;
 echo "DEV=\\\$(ip link | head -3 | tail -1 | awk '{print \\\$2}' | sed -e 's/://')
 MASK=\\\$(ip addr show \\\$DEV | grep 'inet ' | awk '{print \\\$2}' | sed -e 's/.*\\///;q')
 ip addr show \\\$DEV
-kill \\\$(pidof dhclient)
-ip addr flush dev \\\$DEV
-ip addr add ${spoofipaddr}/\\\$MASK dev \\\$DEV
+nmcli device modify \\\$DEV ipv4.method manual ipv4.addr ${spoofipaddr}/\\\$MASK
+sleep 1
 ip addr show \\\$DEV
 sleep 1
 ping -c 1 ${networkipaddr}
-ip link set \\\$DEV down
-ip addr flush dev \\\$DEV
-ip addr add ${guestip}/\\\$MASK dev \\\$DEV
-ip link set \\\$DEV up
+nmcli device modify \\\$DEV ipv4.method auto
 ip addr show \\\$DEV" > /test.sh
 EOF
 diag $cmdfile;