tsort: use iterative dfs to prevent stack overflows

[Nekrolm]

Rewrite DFS method in iterative way to avoid stack overflows

Closes #8695

PR is on top of #8694
but changes are independent. Only top commit can be cherry-picked, if needed

[sylvestre]

please add a test that trigger the stackoverflow

[codspeed-hq]

CodSpeed Performance Report

Merging #8737 will not alter performance

_{Comparing Nekrolm:tsort-no-recursion (129d362) with main (5c15d79)}

Summary

✅ 41 untouched
⏩ 64 skipped¹

Footnotes

1. 64 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/misc/tee (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/timeout/timeout (passes in this run but fails in the 'main' branch)

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/timeout/timeout (passes in this run but fails in the 'main' branch)

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/misc/tee (fails in this run but passes in the 'main' branch)

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/misc/tee (passes in this run but fails in the 'main' branch)

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/misc/tee (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/overlay-headers (passes in this run but fails in the 'main' branch)