`tools` and `parallel` should be added to suggests

[jangorecki]

• tools used in fread and frollapply
• parallel used in frollapply

adding parallel to suggests causes codecov GH job to get stuck
therefore I think the proper path to close this issue is reproduce problem using minimal example using only parallel package and submit it to covr repository, and then apply proposed solution here.

[ANAMASGARD]

@jangorecki I've submitted PR #7403 with the proposed solution:

• Added tools and parallel to DESCRIPTION Suggests field
• Added 4 tests (2345.01-2345.04) to verify functionality
• Updated NEWS.md

All 12,072 local tests pass. The PR is ready for review.

Regarding the codecov hang issue you mentioned - the CI will reveal if this occurs, and if so, we can create a minimal example for the covr repository as you suggested.