build: `pixi` environment setup

[hameerabbasi]

What type of PR is this? (check all applicable)

• [ ] 💾 Refactor
• [ ] 🪄 Feature
• [ ] 🐞 Bug Fix
• [ ] 🔧 Optimization
• [ ] 📚 Documentation
• [ ] 🧪 Test
• [x] 🛠️ Other

Checklist

• [x] Code follows style guide
• [ ] Tests added
• [ ] Documented the changes

---

Please explain your changes below.

Allows for a development workflow using the pixi package manager.

[codspeed-hq[bot]]

CodSpeed Performance Report

Merging #780 will degrade performances by 10.18%

_{Comparing hameerabbasi:pixi (ee6c931) with main (0f7be70)}

Summary

❌ 1 regressions ✅ 339 untouched benchmarks

:warning: Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	hameerabbasi:pixi	Change
❌	test_index_slice[side=100-rank=2-format='gcxs']	2.4 ms	2.6 ms	-10.18%