Add solana pay guide banner

Author: yashovardhan

src/pages/guides/solana-pay.mdx

@@ -1,6 +1,6 @@
 ---
 title: Integrate Solana Pay with Web3Auth
-image: "guides/guides-banners/solana.png"
+image: "guides/guides-banners/solana-pay.png"
 description:
   Learn how to integrate Solana Pay QR code payments with Web3Auth embedded wallets in your React
   application.
@@ -17,7 +17,7 @@ import Tabs from "@theme/Tabs";
 <SEO
   title="Integrate Solana Pay with Web3Auth"
   description="Learn how to integrate Solana Pay QR code payments with Web3Auth embedded wallets in your React application."
-  image="https://web3auth.io/docs/guides/guides-banners/multi.png"
+  image="https://web3auth.io/docs/guides/guides-banners/solana-pay.png"
   slug="/guides/solana-pay"
 />