chore: remove extend dependency

[gameroman]

Checklist

• npm test passes (tip: npm run lint-fix can correct most style issues)
• tests are included
• documentation is changed or added

[CLAassistant]

All committers have signed the CLA.

[pyrooka]

Hey @gameroman, thanks for the contribution. We'll try to look into the PR soon, but I'd like to ask two things in the meantime:

1. Sign off all your commits in the branch, otherwise the DCO check will keep failing
2. Since the purpose of this PR is to remove the extend dependency from the project, it should be also removed from the package.json - along with package-lock.json -, right?

[diatrcz]

Hi @gameroman, thank you for the contribution. Additionally to the change requests:

1. As stated above, please sign your commits so DCO stops failing and remove extend from package.json and package-lock.json.
2. Please keep the branch up to date with the main branch.

[gameroman]

Thank you for the review, I’ll fix everything when I get back👍

[diatrcz]

The changes look good. However, the dependency is still listed in devDependencies. To complete the removal of the extend dependency, it should also be removed from there, even if this requires additional updates to the test codebase.

[gameroman]

Weird, not sure why npm ci is failing. I've ran it locally and the lockfile is up-to-date