chore: replace nyc with c8 for coverage reporting in `package.jso…

…n` (#124)

This pull request includes changes to the `package.json` file to update
the test coverage tool and dependencies. The most important changes
include replacing `nyc` with `c8` for test coverage and updating the
dependencies accordingly.

Changes to test coverage tool:

*
[`package.json`](diffhunk://#diff-7ae45ad102eab3b6d7e7896acd08c427a9b25b346470d7bc6507b6481575d519L39-R39):
Replaced `nyc` with `c8` for the `coverage` script.

Dependency updates:

*
[`package.json`](diffhunk://#diff-7ae45ad102eab3b6d7e7896acd08c427a9b25b346470d7bc6507b6481575d519R59):
Added `c8` as a new dependency.
*
[`package.json`](diffhunk://#diff-7ae45ad102eab3b6d7e7896acd08c427a9b25b346470d7bc6507b6481575d519L69):
Removed `nyc` from the dependencies.