Separate linting and testing in npm scripts

[romaricpascal]

What

Change the npm script running the linting from pretest to lint so it doesn't run before the test command automatically.
Update the test workflow to run both the lint and and test scripts so we keep the same visibility on code quality

Why

Misformatted code may still pass the tests, but we can't know until we fix the linting at the moment. This delay is unnecessary as linting and tests can happily run alongside one another rather than one after the other as they do now

Done when

• Linting is run by npm run lint
• The test workflow runs both lint and test