Deduplicate tests

[oech3]

test_separately is a duplicated of

coreutils/.github/workflows/CICD.yml

Lines 852 to 861 in adf36f9

	- name: Test
	if: matrix.job.skip-tests != true
	shell: bash
	run: |
	## Test
	${{ steps.vars.outputs.CARGO_CMD }} ${{ steps.vars.outputs.CARGO_CMD_OPTIONS }} test --target=${{ matrix.job.target }} \
	${{ steps.vars.outputs.CARGO_TEST_OPTIONS}} ${{ matrix.job.cargo-options }} ${{ steps.vars.outputs.CARGO_FEATURES_OPTION }} ${{ steps.vars.outputs.CARGO_DEFAULT_FEATURES_OPTION }} \
	${{ steps.dep_vars.outputs.CARGO_UTILITY_LIST_OPTIONS }} -p coreutils
	env:
	RUST_BACKTRACE: "1"

existing just for better appearance. But it is inefficient (both for time and caching).

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/tail/inotify-dir-recreate (passes in this run but fails in the 'main' branch)