Default output dir for integration tests causes issues with pre-commit checks

The default output directory for integration tests is output/ directory, which can cause issues when these tests are run locally.

As part of integration tests we clone Git repository under output/. Now if we run make check without removing output/, pre-commit picks up files in these cloned repositories (even though output is part of Macaron's .gitignore) based on their individual .gitignore files.

I can think of two solutions:

1. Use a path outside the current workspace for integration test output directory, but picking a path that would also work on GitHub Actions Runner might not be straightforward.
2. Clean up and remove the integration tests output directory after tests finish (which will make tests slower as we won't cache the cloned repositories anymore).

Start with scripts/dev_scripts/integration_tests.sh, especially the default output/ path, then inspect .gitignore behavior and the make check pre-commit flow. Compare the two proposed approaches against local runs and GitHub Actions; done means integration-test clones no longer cause unrelated files to be checked by make check.