Upgrade c8 to version 11.0.0

This is a major version bump, but the changelog at
https://github.com/bcoe/c8/releases/v11.0.0 doesn't indicate any
breaking changes that should impact us.

Author: timvandermeij

package-lock.json

@@ -17,7 +17,7 @@
     "babel-loader": "^10.0.0",
     "babel-plugin-add-header-comment": "^1.0.3",
     "babel-plugin-istanbul": "^7.0.1",
-    "c8": "^10.1.3",
+    "c8": "^11.0.0",
     "cached-iterable": "^0.3.0",
     "caniuse-lite": "^1.0.30001775",
     "core-js": "^3.48.0",