Feature/demean accelerated

[schroedk]

This PR implements a simple version of the Iron-Tucks acceleration.

Closes #357

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 3 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
pyfixest/estimation/demean_.py	33.33%	2 Missing ⚠️
pyfixest/core/demean_accelerated.py	80.00%	1 Missing ⚠️

Flag	Coverage Δ
core-tests	75.59% <66.66%> (-0.02%)	⬇️
tests-extended	?
tests-vs-r	16.18% <55.55%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
pyfixest/estimation/backends.py	73.33% <100.00%> (+0.91%)	⬆️
pyfixest/estimation/literals.py	87.50% <ø> (ø)
pyfixest/core/demean_accelerated.py	80.00% <80.00%> (ø)
pyfixest/estimation/demean_.py	55.11% <33.33%> (-0.53%)	⬇️

... and 7 files with indirect coverage changes

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[s3alfisc]

@schroedk just rebased / merged changes from master in here (new features plus I moved to using a pixi toml, plus the dev env no longer installs on windows due to compatibility challenges).

As before, you can build the Rust bindings by typing

pixi r -e dev maturin-develop

and run the benchmarks via

pixi run -e dev pytest  tests/test_demean.py::test_demean_complex_fixed_effects

[s3alfisc]

Benchmarks of the accelerated vs regular rust vs fixest and FixedEffectsModels.jl. Looks like good progress to me!