seq: Avoid allocating arbitrarily large bigints (cap set to 10^{4932}…

[aweinstock314]

… for GNU compatibility).

seq: Avoid panicing on decimals smaller than 10^{-65535}.

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/rm/isatty. tests/rm/isatty is passing on 'main'. Maybe you have to rebase?
Skipping an intermittent issue tests/date/resolution (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)
Note: The gnu test tests/dd/no-allocate is now being skipped but was previously passing.

[codspeed-hq]

Merging this PR will improve performance by ×33

⚡ 2 improved benchmarks
✅ 296 untouched benchmarks
⏩ 48 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Memory	seq_large_integers	52.8 KB	7.7 KB	×6.9
⚡	Simulation	seq_large_integers	2,040.8 µs	61.7 µs	×33

---

_{Comparing Zellic:seq-bound-bigints (a0d8d12) with main (53200b3)}

Footnotes

1. 48 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:

Skipping an intermittent issue tests/date/resolution (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/pr/bounded-memory (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tty/tty-eof (passes in this run but fails in the 'main' branch)
Note: The gnu test tests/printf/printf-surprise is now being skipped but was previously passing.

[oech3]

needed to update https://github.com/uutils/coreutils/blob/main/docs/src/extensions.md#seq