feat(biome_css_analyzer): noDuplicateCustomProperties

[chansuke]

Summary

Fixes #2806

Test Plan

[codspeed-hq]

CodSpeed Performance Report

Merging #2783 will degrade performances by 52.46%

_{Comparing chansuke:feat/declaration-block-no-duplicate-custom-properties (52bdeb4) with main (e50a3a4)}

Summary

⚡ 1 improvements
❌ 4 regressions
✅ 102 untouched benchmarks

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

Benchmarks breakdown

	Benchmark	main	chansuke:feat/declaration-block-no-duplicate-custom-properties	Change
❌	css_analyzer[bootstrap_18416142857265205439.css]	124.8 ms	252.1 ms	-50.52%
❌	css_analyzer[bulma_5641719244145477318.css]	433.1 ms	766.7 ms	-43.52%
❌	css_analyzer[foundation_11602414662825430680.css]	83 ms	158.1 ms	-47.51%
❌	css_analyzer[tachyons_11778168428173736564.css]	70.6 ms	148.4 ms	-52.46%
⚡	pure_9395922602181450299.css[cached]	3.6 ms	3.3 ms	+7.1%

[ematipico]

I wonder if we should start writing a semantic model.

I think this rule would benefit from it

[chansuke]

@ematipico
Thank you for your feedback!
Would it be possible for me to contribute to the creation of a semantic model for CSS?

[ematipico]

@ematipico Thank you for your feedback! Would it be possible for me to contribute to the creation of a semantic model for CSS?

Sure, I suggest talking with @togami2864, I know he has plans about it

[togami2864]

The linked issue is #2806, not #2784