Integration tests should run integration tests, not unit tests, too

[edandylytics]

Fixes an issue where unit tests ran twice. In addition to being run with nx test-unit api, they were run with nx test-integration api because the integration jest config just ran all spec files it found. This PR updates the integration jest config to just run tests in the integration folder.

You can see the issue in this CI run. The app config unit tests runs here (line 77) and again here (line 888).

Now, the unit tests just run once, as unit tests.

You can check the totals to verify we're not dropping tests:

Before

Unit tests

Test Suites: 3 passed, 3 total
Tests:       35 passed, 35 total

Integration tests

Test Suites: 15 passed, 15 total
Tests:       372 passed, 372 total

After

Unit

Test Suites: 3 passed, 3 total
Tests:       35 passed, 35 total

Integration

Test Suites: 12 passed, 12 total
Tests:       337 passed, 337 total

372 - 25 = 337

[amazon-inspector-ohio]

⏳ I'm reviewing this pull request for security vulnerabilities and code quality issues. I'll provide an update when I'm done

[snyk-io-us]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues

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[amazon-inspector-ohio]

✅ I finished the code review, and didn't find any security or code quality issues.