Lint dependencies in CI

[Mrtenz]

In the extension, and some other repositories, we use depcheck to lint dependencies. This was never added to the module template however. It can be useful to remove unnecessary dependencies, so I've changed it to run in CI.

[Mrtenz]

Makes sense! Is there a reason why this couldn't be incorporated into yarn lint though?

Not really. 😅 That makes more sense. I've removed the separate workflow and added depcheck to yarn lint (and yarn lint:fix, even though it doesn't fix anything).