Release v2.4.0

Changelog: v2.3.1...v2.4.0

Build

Bump @embroider/test-setup from 0.47.0 to 0.47.1 (#166)

Bump ember-cli-htmlbars from 5.7.1 to 6.0.0 (#167)

Update ember-cli to 3.28.3 (#168)

Deduplicate packages (#168)

See https://github.com/atlassian/yarn-deduplicate.

Chore

Refine information in package.json (#169)

Add contributors to README (#171)

CI

Run workflow tag-release-publish only after lint & tests passed (#163)

Make the workflow tag-release-publish waits for the workflow CI to finish, so that they run sequentially (the same way jobs' steps are run sequentially).

Ensure only 1 workflow runs at a time (#163)

Surprisingly, while a new run of the workflow is triggered when pushing new changes, any previous workflow still running is not cancelled, resulting in a waste of resources.

We now use the concurrency setting to ensure that only a single workflow, using the same concurrency group, will run at a time.

Lint yarn.lock file to spot malicious attacks (#163)

• https://snyk.io/blog/why-npm-lockfiles-can-be-a-security-blindspot-for-injecting-malicious-modules
• https://github.com/lirantal/lockfile-lint

Fix empty concurrency group's name (#165)

Previously the concurrency group's name was empty when running on master (see the faulty run) because the context ${{ github.head_ref }} is only available in PR-related events.

The group's name is now prefixed with ci- to ensure it will never be empty.

Reuse organisation's workflow to run lint & tests (#168)

Reuse organisation's workflow to run tag & publish (#168)

Stop testing against Ember.js v3.16 (#168)

This version has been discontinued in August 2020 and is no longer maintained:
https://emberjs.com/releases/lts/