fix: include TEST_FILE_PATTERNS with empty entry

[ojeytonwilliams]

Hey @webpro, we've been running into an issue where knip would flag our test files as being unused: https://github.com/freeCodeCamp/freeCodeCamp/actions/runs/4466295333/jobs/7844299421#step:6:193

From what I can see, this happens because our workspace config is

    "client": {
// snipped
      "entry": [],
      "project": ["**/*.{js,ts,tsx}"],
// snipped 
    },

It was a relatively small change to get things working again, so I figured a PR was in order.

Hope this helps.

[webpro]

Thanks for this pull request, @ojeytonwilliams. Using an empty entry: [] is really what I intend it to be: use no entry files. When omitted, it means to use the default config for entry files.

I dug a bit deeper and the issue seems to be something different. I think the issue can be fixed in the FCC config, so I'm going to close this one.

[ojeytonwilliams]

Sure, I understand. Thanks for taking a look and for updating fCC's config.