[Docs] .NET Fix LoginWithOtp Example (#5843)

Closes TOOL-2863

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---

## PR-Codex overview
This PR focuses on simplifying the OTP login process in the `InAppWallet` by removing the `canRetry` variable and related conditional logic, providing a more straightforward approach for handling OTP submissions.

### Detailed summary
- Removed the `canRetry` variable from the `LoginWithOtp` method calls.
- Simplified the OTP login logic by eliminating the retry checks.
- Added comments to indicate where to implement error handling and retries if needed.

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<!-- end pr-codex -->

Author: 0xFirekeeper

apps/portal/src/app/dotnet/wallets/providers/in-app-wallet/page.mdx

@@ -46,7 +46,7 @@ var isConnected = await wallet.IsConnected();
 
 // Email & Phone (OTP)
 await wallet.SendOTP(); // and fetch the otp
-var (address, canRetry) = await wallet.LoginWithOtp("userEnteredOTP");
+var address = await wallet.LoginWithOtp("userEnteredOTP"); // try catch and retry if needed
 
 // Socials (OAuth)
 var address = await wallet.LoginWithOauth(
@@ -121,12 +121,8 @@ await wallet.SendOTP();
 **Submit OTP:** Once the user receives the OTP, they submit it back to the application, which then calls LoginWithOtp on the InAppWallet instance to verify the OTP and complete the login process.
 
 ```csharp
-var (address, canRetry) = await wallet.LoginWithOtp("userEnteredOTP");
-if (address != null) {
-    // Login successful
-} else if (canRetry) {
-    // Ask user to retry entering OTP
-}
+var address = await wallet.LoginWithOtp("userEnteredOTP");
+// If this fails, feel free to catch and take in another OTP and retry the login process
 ```
 
 ## Example
@@ -143,18 +139,7 @@ if (!await inAppWallet.IsConnected())
     await inAppWallet.SendOTP();
     Console.WriteLine("Please submit the OTP.");
     var otp = Console.ReadLine();
-    (var inAppWalletAddress, var canRetry) = await inAppWallet.LoginWithOtp(otp);
-    if (inAppWalletAddress == null && canRetry)
-    {
-        Console.WriteLine("Please submit the OTP again.");
-        otp = Console.ReadLine();
-        (inAppWalletAddress, _) = await inAppWallet.LoginWithOtp(otp);
-    }
-    if (inAppWalletAddress == null)
-    {
-        Console.WriteLine("OTP login failed. Please try again.");
-        return;
-    }
+    var inAppWalletAddress = await inAppWallet.LoginWithOtp(otp); // try catch and retry if needed
 }
 
 Console.WriteLine($"InAppWallet address: {await inAppWallet.GetAddress()}");