Dashboard: Fix theme for BuyWidget in chain page (#7583)

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## PR-Codex overview
This PR enhances the `BuyFundsSection` component by integrating theme support for the `BuyWidget` using the `useTheme` hook from `next-themes`. It adjusts the widget's theme based on the current application theme.

### Detailed summary
- Added `useTheme` hook to access the current theme.
- Imported `getSDKTheme` utility for theme handling.
- Passed the correct theme to the `BuyWidget` based on whether the theme is "dark" or "light".

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<!-- This is an auto-generated comment: release notes by coderabbit.ai -->

## Summary by CodeRabbit

* **New Features**
  * The Buy Funds section now adapts its appearance based on your selected theme (light or dark), providing a more consistent and personalized user experience.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: MananTank

apps/dashboard/src/app/(app)/(dashboard)/(chain)/[chain_id]/(chainPage)/components/client/BuyFundsSection.tsx

@@ -1,19 +1,23 @@
 "use client";
+import { useTheme } from "next-themes";
 import { defineChain, type ThirdwebClient } from "thirdweb";
 import type { ChainMetadata } from "thirdweb/chains";
 import { BuyWidget } from "thirdweb/react";
+import { getSDKTheme } from "@/utils/sdk-component-theme";
 
 export function BuyFundsSection(props: {
   chain: ChainMetadata;
   client: ThirdwebClient;
 }) {
+  const { theme } = useTheme();
   return (
     <section className="flex flex-col gap-4 items-center justify-center">
       <BuyWidget
         amount="0"
         // eslint-disable-next-line no-restricted-syntax
         chain={defineChain(props.chain.chainId)}
         client={props.client}
+        theme={getSDKTheme(theme === "dark" ? "dark" : "light")}
       />
     </section>
   );