😈 Improvement - Make `ethers` a optional peer dependency

### Proposal name

Make `ethers` a optional peer dependency for Core SDK

### Describe the Proposal

- Core relies on `viem` for all evm utils
- `ethers` should not be a dep of core.
- For using `ethers` for universalSigner we  should look into ways to make it as optional peer dep since not all developers will use it.  

### Use Case

- Makes sdk less bulky

### Current Limitations

-