Fix NX-OS get_bgp_neighbors by adding new state

[sk4mi]

Fix unrecognised BGP neighbour state from nxos 10.2(3)

# sh ver
[...]
Software
  BIOS: version 05.51
  NXOS: version 10.3(6) [Maintenance Release]
  BIOS compile time:  11/29/2023
  NXOS image file is: bootflash:///nxos64-cs.10.3.6.M.bin
  NXOS compile time:  8/20/2024 12:00:00 [08/20/2024 11:31:13]

Hardware
  cisco Nexus9000 C93240YC-FX2 Chassis
  Intel(R) Xeon(R) CPU D-1526 @ 1.80GHz with 16312720 kB of memory.
  Processor Board ID *********
  bootflash:  115805708 kB

th2-prod(config)# sh ip bgp summary
BGP summary information for VRF default, address family IPv4 Unicast
BGP router identifier ....., local AS number .....
BGP table version is 7933588, IPv4 Unicast config peers 13, capable peers 12
15888 network entries and 31199 paths using 6109152 bytes of memory
BGP attribute entries [4247/1528920], BGP AS path entries [2550/44528]
BGP community entries [672/43016], BGP clusterlist entries [0/0]
4293583822 received paths for inbound soft reconfiguration
4293583822 identical, 0 modified, 0 filtered received paths using 0 bytes

Neighbor        V    AS    MsgRcvd    MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
*****                4  *****          0          0        0    0    0    11w4d Shut (Admin)