chore: remove Circle-CI, fix GHA

[dblock]

🚀 Why this change?

Build goes to green again.

• Removes Circle-CI. Looks dead? Unused?
• Moves smoke tests to GitHub Actions.
• Run tests/lints/etc. on pull_request.
• Renames jobs to tests (plural) to be consistent.
• Locks sphinx doc dependencies to those compatible with v4.3.0.
• https://github.com/ungrim97/Dredd-Hooks doesn't have functioning CI anymore (Travis CI is RIP), so links in docs removed
• Fixes yarn docs:lint, but loses some anchors that no longer work and I couldn't find easy replacements for

See https://github.com/dblock/dredd/actions for everything passing.

📝 Related issues and Pull Requests

#2294

✅ What didn't I forget?

• To write docs
• To write tests
• To put Conventional Changelog prefixes in front of all my commits and run npm run lint

[kylef]

supercharge/mongodb-github-action@1.6.0 is not allowed to be used in apiaryio/dredd.

We're not going to be able to use this, perhaps it is worth removing this file/smoke tests from CI. Arguably merging this would still be better than current situation without smoke tests.

[dblock]

Not a problem. Updated to use GitHub's services, I was lazy and copy pasting from an older project ;)

Passing build in https://github.com/dblock/dredd/actions/runs/9043948597/job/24852077761.