Use Safe MultiSend contract

[anajuliabit]

This PR replaces the Multicall3 with Safe MultiSend v1.3.0. Is the same contract safe uses for batch transaction, this is how it shows in the UI

https://etherscan.io/address/0x40a2accbd92bca938b02010e17a5b8929b49130d#code

[Copilot]

Pull Request Overview

This PR replaces the legacy Multicall3 contract with Safe MultiSend v1.3.0 to support batch transactions using an updated bytecode and calldata encoding strategy. Key changes include:

• Updating the constant in Constants.sol from MULTICALL_BYTECODE to MULTISEND_BYTECODE.
• Modifying the proposal contracts (MultisigProposal.sol and GovernorBravoProposal.sol) to generate and verify calldata for the MultiSend contract.
• Adjusting tests in MultisigProposal.t.sol to reflect the new MultiSend encoding and removing unused code constructs.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
utils/Constants.sol	Updated constant definition to use the Safe MultiSend bytecode.
test/MultisigProposal.t.sol	Revised test assertions and removed unused struct definitions.
src/proposals/MultisigProposal.sol	Refactored calldata generation to use the MultiSend encoding.
src/proposals/GovernorBravoProposal.sol	Minor refactoring for import ordering and simulation updates.

Comments suppressed due to low confidence (1)

test/MultisigProposal.t.sol:6

• [nitpick] The removal of the unused 'Call3Value' struct improves maintainability; ensure similar unused code is cleaned up elsewhere.

import {Addresses} from "@addresses/Addresses.sol";