roi: remove Building interface

added in 8d13db9 but never used

ts/roi.ts

@@ -156,9 +156,3 @@ interface MatPrice {
 	amount: number
 	vwap_7d: number
 }
-
-interface Building {
-	building_type: 'INFRASTRUCTURE' | 'PLANETARY' | 'PRODUCTION';
-	building_ticker: string;
-	expertise: keyof typeof expertise;
-}