refactor: simplify type assertions

Author: nelsonlaidev

src/components/ui/chart.tsx

@@ -302,13 +302,13 @@ function getPayloadConfigFromPayload(config: ChartConfig, payload: unknown, key:
   let configLabelKey: string = key
 
   if (key in payload && typeof payload[key as keyof typeof payload] === 'string') {
-    configLabelKey = payload[key as keyof typeof payload] as string
+    configLabelKey = payload[key as keyof typeof payload]
   } else if (
     payloadPayload &&
     key in payloadPayload &&
     typeof payloadPayload[key as keyof typeof payloadPayload] === 'string'
   ) {
-    configLabelKey = payloadPayload[key as keyof typeof payloadPayload] as string
+    configLabelKey = payloadPayload[key as keyof typeof payloadPayload]
   }
 
   return configLabelKey in config ? config[configLabelKey] : config[key]