date/test: %x format specifier respects locale settings

[sylvestre]

The test is ignored as we didn't fix it yet
#10284

[codspeed-hq]

Merging this PR will improve performance by 5.28%

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

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Memory	cp_large_file[16]	118.9 KB	112.9 KB	+5.28%

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_{Comparing sylvestre:issue-10284 (7d48ca3) with main (2a044db)}

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. ↩

[ChrisDryden]

Just thought of this while merging but probably better to add the GitHub issue link instead, since the other link is in the issue anyways