solc warnings with export-abi --json

[afosan]

Not a critical issue at all, but cargo stylus export-abi --json prints out solc warnings, which does not seem ideal. Example from repo.

Warning: SPDX license identifier not provided in source file. Before publishing, consider adding a comment containing "SPDX-License-Identifier: <SPDX-License>" to each source file. Use "SPDX-License-Identifier: UNLICENSED" for non-open-source code. Please see https://spdx.org for more information.
--> <stdin>

Warning: Source file does not specify required compiler version! Consider adding "pragma solidity ^0.8.22;"
--> <stdin>


======= <stdin>:IContract =======
Contract JSON ABI
[{"inputs":[],"name":"withMutableReferenceToSelf","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"withReferenceToSelf","outputs":[],"stateMutability":"view","type":"function"},{"inputs":[],"name":"withoutSelf","outputs":[],"stateMutability":"pure","type":"function"}]

[rauljordan]

Thanks @afosan for reporting ! fixed in OffchainLabs/stylus-sdk-rs#101