Fix import contract not working in dashboard (#3784)

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## PR-Codex overview
This PR updates the `useRegistry.ts` and `hooks.ts` files to include a new `account` value of `300000n`.

### Detailed summary
- Updated `useRegistry.ts` and `hooks.ts` with `account: 300000n` value
- Called `deployContext.nextStep()` after the changes

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apps/dashboard/src/@3rdweb-sdk/react/hooks/useRegistry.ts

@@ -148,6 +148,7 @@ export function useAddContractMutation() {
           chainId: data.chainId,
         },
         account,
+        300000n,
       );
     },
     {

apps/dashboard/src/components/contract-components/hooks.ts

@@ -840,6 +840,7 @@ export function useCustomContractDeployMutation(
               chainId,
             },
             account,
+            300000n,
           );
 
           deployContext.nextStep();