Added Check to CeloDistributionSchedule activate function

[soloseng]

Description

Added a check that prevents activating the CeloDistributionSchedule contract if the distributionSchedule contract address if not set in CELO token contract.

Previously, it was expected that the CeloDistributionSchedule address would be manually set in the GoldToken contract by calling setCeloTokenDistributionSchedule(). This was expected to be done before calling activate() in the CeloDistributionSchedule. However, the CeloDistributionSchedule contract did not verify that the CeloDistributionSchedule address was set in the GoldToken contract, allowing for the CeloDistributionSchedule to be incorrectly activated.

These new changes get the CeloDistributionSchedule address from the registry, instead of setting it in the GoldToken contract. Hence, no longer requiring that the CeloDistributionSchedule address be manually set in the GoldToken contract before activating the CeloDistributionSchedule contract.

Tested

unit tested

[gitguardian]

⚠️ GitGuardian has uncovered 1 secret following the scan of your pull request.

Please consider investigating the findings and remediating the incidents. Failure to do so may lead to compromising the associated services or software components.

🔎 Detected hardcoded secret in your pull request

GitGuardian id	GitGuardian status	Secret	Commit	Filename
10538986	Triggered	Generic High Entropy Secret	e379b5c	packages/protocol/scripts/foundry/constants.sh	View secret

🛠 Guidelines to remediate hardcoded secrets

1. Understand the implications of revoking this secret by investigating where it is used in your code.
2. Replace and store your secret safely. Learn here the best practices.
3. Revoke and rotate this secret.
4. If possible, rewrite git history. Rewriting git history is not a trivial act. You might completely break other contributing developers' workflow and you risk accidentally deleting legitimate data.

To avoid such incidents in the future consider

• following these best practices for managing and storing secrets including API keys and other credentials
• install secret detection on pre-commit to catch secret before it leaves your machine and ease remediation.

---

^{🦉 GitGuardian detects secrets in your source code to help developers and security teams secure the modern development process. You are seeing this because you or someone else with access to this repository has authorized GitGuardian to scan your pull request.}

[arthurgousset]

Left a couple nit comments, but looks good to me. I like how you wrote the two new unit tests. It's clever to expect the contract to revert.

Nit: registryAddress and proxyAdminAddress (as examples) are constants that could live in test-sol/constants.sol. Probably not worth refactoring in this PR, but something that might be worth doing separately.

[arthurgousset]

I'm not 100% sure I understand the original bug, and how this PR fixes it, so not super comfortable approving. But left some nit comments from reading through the PR.

I mistakenly approved the PR when I meant to leave a comment

[soloseng]

I'm not 100% sure I understand the original bug, and how this PR fixes it, so not super comfortable approving. But left some nit comments from reading through the PR.

Updated the PR description to make it more clear what the changes are and why they were needed.

[arthurgousset]

Pending this conversation the changes look good to me. But, I'm always a little nervous approving changes to core contracts. So take my approval with a pinch of salt. I'd prefer if @martinvol or @pahor167 gave this an approval too.