Correct code block syntax in changelog.md

[saulshanabrook]

Fixed code block formatting in changelog.

[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #359 will degrade performances by 16.79%

_{Comparing saulshanabrook-patch-3 (21d2cbb) with main (a46b180)¹}

Summary

❌ 1 regression
✅ 6 untouched

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

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
❌	test_jit[lda]	7.1 s	8.5 s	-16.79%

Footnotes

1. No successful run was found on main (21d2cbb) during the generation of this report, so a46b180 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩