Fix type error

Author: ooboqoo

src/main/take-screenshot.ts

@@ -16,6 +16,7 @@ export function takeScreenshot(): Promise<string | void> {
         const base64Data = screenshot.toString('base64')
         return base64Data
       }
+      return undefined
     })
     .catch((error) => {
       console.error('Error taking screenshot:', error)

src/renderer/src/coder/AppContent.tsx

@@ -47,6 +47,7 @@ export function AppContent() {
 
       return () => clearTimeout(timer)
     }
+    return undefined
   }, [solutionChunks, isLoading, setIsLoading])
 
   useEffect(() => {