Fix: Add loopback network advertisements to IPv4 AF on leaf3,4,7,8

Added network statements for loopback addresses in IPv4 address family:
- Leaf3/4: network 10.0.250.13/32, 10.0.250.14/32, 10.0.255.12/32
- Leaf7/8: network 10.0.250.17/32, 10.0.250.18/32, 10.0.255.14/32

This ensures EVPN BGP sessions establish properly on redeploy.
Previously these were only in the VRF gold section.

configs/leaf3.cfg

@@ -167,6 +167,8 @@ router bgp 65002
       neighbor underlay_ibgp activate
       network 10.0.250.13/32
       network 10.0.255.12/32
+      network 10.0.250.13/32
+      network 10.0.255.12/32
    !
    ! EVPN address family
    address-family evpn