Fix: Update contracts license to MIT

[karacurt]

Previous contracts licenses were UNLICENSED. After a discussion on Slack we decided to use MIT

[octane-security-app-dev]

Summary by Octane

New Contracts

No new contracts were added in this PR.

Updated Contracts

• TokenFaucet.sol: License changed to MIT; no primary functionality or features altered.
• TokenSender.sol: License updated from UNLICENSED to MIT, enabling broader usage and distribution.
• IStaker.sol: The license was changed from UNLICENSED to MIT, allowing broader usage and distribution.
• tokens.sol: License changed from UNLICENSED to MIT; no primary functionality or feature modifications noted.
• PositionMetadata.sol: Changed license to MIT; no primary functionality or feature modifications noted.
• Staker.sol: Updated license to MIT and retained ERC20 functionality via an OpenZeppelin import.
• data.sol: SPDX license updated from UNLICENSED to MIT for broader usage permissions.
• ERC20.sol: Updated smart contract license to MIT and revised author contact email.

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🔗 Commit Hash: 49b22e1

[octane-security-app-dev]

Overview

Octane AI analysis has finished. No vulnerabilities were found. Cheers! 🎉🎉🎉

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🔗 Commit Hash: 49b22e1

[zomglings]

lgtm