build(deps-dev): bump solidity-coverage from 0.7.17 to 0.7.20 (#174)

Bumps [solidity-coverage](https://github.com/sc-forks/solidity-coverage) from 0.7.17 to 0.7.20.
- [Release notes](https://github.com/sc-forks/solidity-coverage/releases)
- [Changelog](https://github.com/sc-forks/solidity-coverage/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sc-forks/solidity-coverage/commits)

---
updated-dependencies:
- dependency-name: solidity-coverage
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

packages/smartcontracts/package.json

@@ -57,7 +57,7 @@
   "devDependencies": {
     "@metamask/eth-sig-util": "^4.0.0",
     "solc": "0.8.6",
-    "solidity-coverage": "^0.7.17",
+    "solidity-coverage": "^0.7.20",
     "typechain": "^4.0.3",
     "solhint": "^3.3.4",
     "@nomiclabs/hardhat-ethers": "^2.0.2",