fix(tracemetrics): Change aggregate table (#102139)

### Summary
Small styling tweaks so it doesn't always expand to the max

Author: k-fish

static/app/views/explore/metrics/metricInfoTabs/aggregatesTab.tsx

@@ -67,7 +67,7 @@ export function AggregatesTab({metricName}: AggregatesTabProps) {
 
   const tableStyle = useMemo(() => {
     return {
-      gridTemplateColumns: `repeat(${fields.length - 1}, min-content) 1fr`,
+      gridTemplateColumns: `repeat(${fields.length}, min-content) 1fr`,
     };
   }, [fields]);