Dashboard: Update faucet amount for injective testnet (#8368)

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## PR-Codex overview
This PR adds a new entry for the `Injective testnet` in the `faucet.ts` file, indicating a change in the configuration for test networks.

### Detailed summary
- Added a new entry for `Injective testnet` with a value of `1` in the configuration.
- The existing entry for `Arc testnet` remains unchanged.

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

## Summary by CodeRabbit

## New Features
* Added support for Injective testnet, enabling faucet claims on this network with customized claim amount configuration.

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

Author: Yash094

apps/dashboard/src/@/utils/faucet.ts

@@ -7,6 +7,8 @@ const customClaimAmounts: Record<number, number> = {
   531050104: 5,
   // Arc testnet
   5042002: 1,
+  // Injective testnet
+  1439: 1,
 };
 
 const defaultClaimAmount = 0.01;