X402 playground chainlist (#8588)

## [Playground] Fix: Exclude deprecated chains from x402 network selector

## Notes for the reviewer

This change enables the existing `disableDeprecated` functionality of the `SingleNetworkSelector` component on the x402 playground page. This ensures that deprecated chains are no longer displayed in the network selection dropdown, consistent with patterns used elsewhere in the codebase.

## How to test

1.  Navigate to `https://playground.thirdweb.com/x402`.
2.  Open the network selector dropdown.
3.  Verify that deprecated chains (e.g., Mumbai) are not listed.

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[Slack Thread](https://thirdwebdev.slack.com/archives/C09DS2CKGP2/p1766589810150189?thread_ts=1766589810.150189&cid=C09DS2CKGP2)

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## PR-Codex overview
This PR introduces a new property to a component, enhancing its functionality by allowing it to disable deprecated features.

### Detailed summary
- Added the `disableDeprecated` property to the `X402LeftSection` component.
- This change modifies the component's behavior, likely affecting how deprecated features are handled.

> ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your question}`

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

## Summary by CodeRabbit

* **Bug Fixes**
  * Updated component configuration to disable deprecated options in the network selector.

<sub>✏️ Tip: You can customize this high-level summary in your review settings.</sub>

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

Author: Yash094

apps/playground-web/src/app/x402/components/X402LeftSection.tsx

@@ -128,6 +128,7 @@ export function X402LeftSection(props: {
               onChange={handleChainChange}
               placeholder="Select a chain"
               className="bg-card"
+              disableDeprecated
             />
           </div>