test-network: fix racy test for address_static

NFT sets must be installed before starting networkd, otherwise some sets may be
installed too late.

Closes #30427

test/test-network/systemd-networkd-tests.py

@@ -2562,10 +2562,10 @@ def verify_address_static(
 
     def test_address_static(self):
         copy_network_unit('25-address-static.network', '12-dummy.netdev', copy_dropins=False)
-        start_networkd()
         self.setup_nftset('addr4', 'ipv4_addr')
         self.setup_nftset('network4', 'ipv4_addr', 'flags interval;')
         self.setup_nftset('ifindex', 'iface_index')
+        start_networkd()
 
         self.wait_online(['dummy98:routable'])