Bump c8 from 8.0.1 to 9.1.0

Bumps [c8](https://github.com/bcoe/c8) from 8.0.1 to 9.1.0.
- [Release notes](https://github.com/bcoe/c8/releases)
- [Changelog](https://github.com/bcoe/c8/blob/main/CHANGELOG.md)
- [Commits](bcoe/c8@v8.0.1...v9.1.0)

---
updated-dependencies:
- dependency-name: c8
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -39,7 +39,7 @@
   "dependencies": {},
   "peerDependencies": {},
   "devDependencies": {
-    "c8": "^8.0.0",
+    "c8": "^9.1.0",
     "codecov": "^3.2.0",
     "oletus": "^4.0.0",
     "rollup": "^4.6.1",