[Maintainers] Switching from SSE to AVX, for Thorium

[Ra2-IFV]

Discussed in #6283

^{Originally posted by Ra2-IFV October 27, 2024}
Modern CPU supports AVX, SSE3 is pretty old enough. Considering the purpose of Thorium, most users should benefit from this.
I have a repo that has all 3 versions of Thorium for different CPU instruction sets. I plan to replace the current manifest with the AVX one, then open a pull request for the rest (SSE3 and AVX2)