Upgrade: Bump nyc from 14.1.1 to 15.1.0

Bumps [nyc](https://github.com/istanbuljs/nyc) from 14.1.1 to 15.1.0.
- [Release notes](https://github.com/istanbuljs/nyc/releases)
- [Changelog](https://github.com/istanbuljs/nyc/blob/master/CHANGELOG.md)
- [Commits](istanbuljs/nyc@v14.1.1...v15.1.0)

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

package.json

@@ -45,7 +45,7 @@
     "babel-preset-power-assert": "^3.0.0",
     "eslint": "^6.2.2",
     "mocha": "^8.1.3",
-    "nyc": "14.1.1",
+    "nyc": "15.1.0",
     "opener": "^1.5.1",
     "p-event": "^4.1.0",
     "power-assert": "^1.6.1",