fix(keyring-eth-ledger-bridge): fix webpack build about non-exported …

…`EIP712Message` type (#140)

Webpack build failed in MM extension complaining `EIP712Message` not
found.

This PR will fix the issue.

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packages/keyring-eth-ledger-bridge/src/ledger-bridge.ts

@@ -1,6 +1,6 @@
 import type LedgerHwAppEth from '@ledgerhq/hw-app-eth';
 import type Transport from '@ledgerhq/hw-transport';
-import { EIP712Message } from '@ledgerhq/types-live';
+import type { EIP712Message } from '@ledgerhq/types-live';
 
 export type GetPublicKeyParams = { hdPath: string };
 export type GetPublicKeyResponse = Awaited<