feat: Add Segmented Ribcage to costs

The Segmented Ribcage has no known source outside a specific Whitsun
egg, much like the Obsidian Chitin Tail. As such, it has been given a
placeholder price that prevents it from being used normally.

bonemarketsolver/data/costs.py

@@ -184,6 +184,10 @@ class Cost(Enum):
     # Khan's Heart, disgruntled academic
     SEARING_ENIGMA = 2*ACTION + 130*INFILTRATING + 2*INTERCEPTED_CABLEGRAM
 
+    # Segmented Ribcage
+    # No consistent source
+    SEGMENTED_RIBCAGE = cp_model.INT32_MAX/4
+
     # Carved Ball of Stygian Ivory
     STYGIAN_IVORY = 250