Backport tests/env/env.sh for better multicall support

[oech3]

Required by #10258

[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)
Congrats! The gnu test tests/ptx/ptx-overrun is no longer failing!

[codspeed-hq]

Merging this PR will improve performance by 4.48%

⚡ 1 improved benchmark
✅ 281 untouched benchmarks
⏩ 38 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Memory	du_wide_tree[(5000, 500)]	1.3 MB	1.2 MB	+4.48%

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_{Comparing oech3:patch-2 (cdf66d5) with main (d7ed3c6)}

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. ↩