remove spelling soft dependency

[pawelru]

You have already have it covered with the following GitHub Action

cards/.github/workflows/check.yaml

Lines 76 to 80 in d3dfc96

	spelling:
	name: Spell Check 🆎
	uses: insightsengineering/r.pkg.template/.github/workflows/spelling.yaml@main
	secrets:
	REPO_GITHUB_TOKEN: ${{ secrets.REPO_GITHUB_TOKEN }}

All the packages (incl. Suggests) are required to build the package which is a part of installing from source. Removing this will make the requirements a little bit smaller and faster to install.

[pawelru]

Same applies for cardx package