pflare:add new package

[stevendargaville]

This add a new package PFLARE (https://github.com/PFLAREProject/PFLARE). It adds methods to PETSc designed for asymmetric linear systems. It depends on PETSc, MPI, BLAS and LAPACK, as well as Python with a variant.

It builds locally on Linux and Mac OSX. I have CI at https://github.com/PFLAREProject/PFLARE_spack that checks spack install succeeds on Ubuntu as well as the one variant. This runs every time the main branch of PFLARE is changed to ensure we don't break anything.

I have added myself as a maintainer and the style has been checked with spack style --fix.

[github-actions]

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Thank you for your contributions!

[hainest]

SHAs confirmed.

[stevendargaville]

@hainest Thanks for the review, I've made the requested changes and added new versions since the PR was opened.

[hainest]

@spackbot fix style

[spackbot-app]

Let me see if I can fix that for you!

[spackbot-app]

I was able to run spack style --fix for you!

spack style --fix

repos/spack_repo/builtin/packages/pflare/package.py
�[1;34m==> �[0mrunning ruff format
1 file left unchanged
�[1;34m==> �[0mrunning ruff check
Found 1 error (1 fixed, 0 remaining).
�[1;34m==> �[0mstyle checks passed

Keep in mind that I cannot fix your flake8 or mypy errors, so if you have any you'll need to fix them and update the pull request. If I was able to push to your branch, if you make further changes you will need to pull from your updated branch before pushing again.

I've updated the branch with style fixes.

[stevendargaville]

Apologies I pushed a commit that included the spack style --fix around the same time the spackbot was triggered. Should be ready to go through the final CI now.

[stevendargaville]

CI is green so I think the PR is ready

[hainest]

LGTM. Thanks for making the suggested fixes!