locale.rs: fix a cfg with collapsible_if

[oech3]

No description provided.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/inotify-dir-recreate (fails in this run but passes in the 'main' branch)
Congrats! The gnu test tests/misc/sync is no longer failing!
Note: The gnu test tests/tail/pipe-f is now being skipped but was previously passing.
Congrats! The gnu test tests/basenc/bounded-memory is now passing!
Congrats! The gnu test tests/expand/bounded-memory is now passing!
Congrats! The gnu test tests/unexpand/bounded-memory is now passing!
Skip an intermittent issue tests/pr/bounded-memory (was skipped on 'main', now failing)

[codspeed-hq]

Merging this PR will not alter performance

✅ 309 untouched benchmarks
⏩ 46 skipped benchmarks¹

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_{Comparing oech3:cif-cfg (3e12ec7) with main (5120da0)}

Footnotes

1. 46 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. ↩

[cakebaker]

Thanks!