coverage: nyc => c8

package.json

@@ -16,9 +16,9 @@
   },
   "scripts": {
     "lint": "eslint --ext js --ext mjs .",
-    "test": "npm run lint && nyc mocha && node support/specsplit.mjs",
+    "test": "npm run lint && c8 mocha && node support/specsplit.mjs",
-    "coverage": "npm run test && nyc report --reporter html",
+    "coverage": "npm run test && c8 report --reporter html",
-    "report-coveralls": "nyc --reporter=lcov mocha",
+    "report-coveralls": "c8 --reporter=lcov mocha",
     "doc": "node support/build_doc.js",
     "gh-doc": "npm run doc && gh-pages -d apidoc -f",
     "demo": "npm run lint && node support/build_demo.js",
@@ -50,6 +50,7 @@
     "ansi": "^0.3.0",
     "autoprefixer-stylus": "^1.0.0",
     "benchmark": "~2.1.0",
+    "c8": "^8.0.1",
     "chai": "^4.2.0",
     "coveralls": "^3.0.4",
     "eslint": "^8.4.1",
@@ -71,7 +72,6 @@
     "mocha": "^9.1.3",
     "ndoc": "^6.0.0",
     "needle": "^3.0.0",
-    "nyc": "^15.0.1",
     "pug-cli": "^1.0.0-alpha6",
     "rollup": "^2.29.0",
     "rollup-plugin-node-polyfills": "^0.2.1",