test: Increase code coverage

[0xNeshi]

Towards #426

Related #799

PR Checklist

• Tests
• Documentation
• Changelog

[netlify]

✅ Deploy Preview for contracts-stylus canceled.

Name	Link
🔨 Latest commit	74c8a13
🔍 Latest deploy log	https://app.netlify.com/projects/contracts-stylus/deploys/68a2fe2a799b660008b667f0

[codecov]

Codecov Report

❌ Patch coverage is 99.92476% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 94.8%. Comparing base (24b543d) to head (74c8a13).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
contracts/src/finance/vesting_wallet.rs	99.5%	1 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
...tracts/src/access/control/extensions/enumerable.rs	100.0% <ø> (+7.9%)	⬆️
contracts/src/access/ownable.rs	100.0% <100.0%> (+8.9%)	⬆️
contracts/src/proxy/beacon/proxy.rs	100.0% <ø> (+9.2%)	⬆️
contracts/src/proxy/beacon/upgradeable.rs	100.0% <ø> (ø)
contracts/src/proxy/erc1967/mod.rs	100.0% <ø> (+10.3%)	⬆️
contracts/src/proxy/erc1967/utils.rs	100.0% <100.0%> (+3.4%)	⬆️
contracts/src/proxy/mod.rs	100.0% <ø> (+10.2%)	⬆️
contracts/src/proxy/utils/uups_upgradeable.rs	96.9% <ø> (+10.0%)	⬆️
contracts/src/token/erc1155/extensions/supply.rs	100.0% <100.0%> (+18.2%)	⬆️
contracts/src/token/erc1155/mod.rs	99.9% <100.0%> (+2.5%)	⬆️
... and 22 more