Use MULTICALL=y at toybox test for faster CI

[oech3]

No description provided.

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/shuf/shuf-reservoir (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/sort/sort-stale-thread-mem (passes in this run but fails in the 'main' branch)

[codspeed-hq]

CodSpeed Performance Report

Merging this PR will improve performance by 4.63%

_{Comparing oech3:patch-10 (c0f67c6) with main (43fcff8)}

Summary

⚡ 2 improved benchmarks
✅ 280 untouched benchmarks
⏩ 38 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Memory	sort_key_field[500000]	32.8 MB	31.4 MB	+4.63%
⚡	Memory	sort_numeric[500000]	48.7 MB	47.3 MB	+3.06%

Footnotes

1. 38 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. ↩

[oech3]

Are symlinks not necessary?

[sylvestre]

Did you evaluate the perf win? Thanks

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tty/tty-eof (fails in this run but passes in the 'main' branch)

[oech3]

About -30 s (with debug build)