feat(CLI): enable linting of cli unit test code

[spirulence]

Issue Description

Select one of:
[ ] Generated codemod is not correct
[ ] Bug in Codemod Studio
[ ] UI/UX improvement request
[X] Feature request

pnpm lint-staged, which is used in pre-commit hooks and in CI, does not seem to catch linting issues in unit tests in the CLI app. I'd like to improve this by enabling linting of unit tests going forward. There aren't too many unit test files right now, so it's a good time for that.

Here's a motivating example where linting did not catch a couple of unused variables in unit test code.

@mohab-sameh I got caught off-guard here by the fact that `pnpm lint-staged` did not catch my unused variables in testing! nice catch. may be room for improvement there.

Originally posted by @spirulence in #1408 (comment)

Steps to Reproduce

1. Navigate to the CLI folder - apps/cli
2. Make a change in a unit test source file that should fail linting, like adding an unused variable or incorrect formatting
3. Stage the change in Git
4. Run pnpm lint-staged

Actual Results

The linter reports no errors.

Expected Results

The linter should report an error and pnpm lint-staged should return a failure exit code.

Technical details

• NodeJS 20