Speeding up tests

[rosecers]

I'll go one by one from #174 and leave this on draft til I'm through. Started with pcovcur and reduced the datasize.

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📚 Documentation preview 📚: https://scikit-matter--190.org.readthedocs.build/en/190/

[rosecers]

@PicoCentauri There was a patch in KernelPCovR that should speed up a lot of things. Can you re-benchmark and see how we're doing?

[PicoCentauri]

I ran the tests with

tox -e tests -- --durations=5 tests/test_kernel_pcovr.py tests/test_sample_pcov_cur.py

and got for the main branch

807.39s call     tests/test_sample_pcov_cur.py::TestPCovCUR::test_multiple_k
211.64s call     tests/test_kernel_pcovr.py::KernelPCovRTestSVDSolvers::test_svd_solvers
25.62s call     tests/test_kernel_pcovr.py::KernelPCovRErrorTest::test_kpcovr_error
25.01s call     tests/test_kernel_pcovr.py::KernelTests::test_kernel_types
23.54s call     tests/test_kernel_pcovr.py::KernelPCovRErrorTest::test_reconstruction_errors

and for the speedup_tests branch

7.86s call     tests/test_kernel_pcovr.py::KernelPCovRTestSVDSolvers::test_svd_solvers
5.92s call     tests/test_sample_pcov_cur.py::TestPCovCUR::test_multiple_k
3.09s call     tests/test_kernel_pcovr.py::KernelPCovRErrorTest::test_reconstruction_errors
2.91s call     tests/test_kernel_pcovr.py::KernelPCovRErrorTest::test_kpcovr_error
2.85s call     tests/test_kernel_pcovr.py::KernelPCovRTestSVDSolvers::test_good_n_components

So it is mhuuuuch better. The CI tests now also only take a minute!

[rosecers]

Great! With your approval we can merge

[PicoCentauri]

🫶