perf: remove SourceMapLineChunk

[SyMind]

No description provided.

[codspeed-hq]

CodSpeed Performance Report

Merging #110 will degrade performances by 21.26%

_{Comparing SyMind:perf-with-indices-v2 (83caf87) with main (920711b)}

Summary

❌ 3 regressions
✅ 2 untouched benchmarks

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

Benchmarks breakdown

	Benchmark	main	SyMind:perf-with-indices-v2	Change
❌	concat_generate_base64	52.6 µs	57 µs	-7.81%
❌	concat_generate_string	49.9 µs	55.4 µs	-9.98%
❌	replace_large_minified_source	81.3 ms	103.3 ms	-21.26%