Closes #23041: Add InfiniBand 2X interface types

Add a 2X (two-lane) InfiniBand group for HDR and later generations, covering
the HDR100, NDR200, and XDR400 breakout links formed by splitting a four-lane
port into two independent two-lane links.

SDR through EDR are omitted deliberately: two-lane breakout only became a
shipping configuration once per-lane rates reached 50 Gbps, so there are no
corresponding products at those generations.

netbox/dcim/choices.py

@@ -1137,6 +1137,11 @@ class InterfaceTypeChoices(ChoiceSet):
     TYPE_INFINIBAND_NDR = 'infiniband-ndr'
     TYPE_INFINIBAND_XDR = 'infiniband-xdr'
 
+    # InfiniBand 2X
+    TYPE_INFINIBAND_HDR_2X = 'infiniband-hdr-2x'
+    TYPE_INFINIBAND_NDR_2X = 'infiniband-ndr-2x'
+    TYPE_INFINIBAND_XDR_2X = 'infiniband-xdr-2x'
+
     # InfiniBand 4X
     TYPE_INFINIBAND_SDR_4X = 'infiniband-sdr-4x'
     TYPE_INFINIBAND_DDR_4X = 'infiniband-ddr-4x'
@@ -1480,6 +1485,14 @@ class InterfaceTypeChoices(ChoiceSet):
                 Choice(TYPE_INFINIBAND_XDR, 'XDR (200 Gbps)'),
             )
         ),
+        (
+            'InfiniBand 2X',
+            (
+                Choice(TYPE_INFINIBAND_HDR_2X, 'HDR 2X (100 Gbps)'),
+                Choice(TYPE_INFINIBAND_NDR_2X, 'NDR 2X (200 Gbps)'),
+                Choice(TYPE_INFINIBAND_XDR_2X, 'XDR 2X (400 Gbps)'),
+            )
+        ),
         (
             'InfiniBand 4X',
             (