Fix CSC/CSR .mT fill-value result

[mtsokol]

Hi @hameerabbasi,

It looks like transposing CSC/CSR drops fill-value. Here's a fix.

[hameerabbasi]

Thanks, @mtsokol!

[hameerabbasi]

Ouch -- looks like the array API tests fail for Finch. Hmm; let's put that into a separate PR to be merged quickly instead of bundling it with #848?

[hameerabbasi]

Looks like it's just one test -- that can be bundled and we can merge-commit this PR instead of squash.

[mtsokol]

Looks like it's just one test -- that can be bundled and we can merge-commit this PR instead of squash.

Done!

[codspeed-hq]

CodSpeed Performance Report

Merging #849 will degrade performances by 44.29%

_{Comparing ms/csr-csc-mT-fix (769a5cd) with main (60c552f)}

Summary

❌ 2 regressions
✅ 338 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
❌	test_index_fancy[side=100-rank=1-format='coo']	757.1 µs	1,359 µs	-44.29%
❌	test_index_slice[side=100-rank=2-format='gcxs']	2 ms	2.8 ms	-27.28%