feat(perf): optimize some custom mod ops

closes: please link all relevant issues

[x] Tests for the changes have been added (for bug fixes / features)
[x] Docs have been added / updated (for bug fixes / features)
[x] Relevant issues are marked as resolved/closed, related issues are linked in the description
[x] Check for breaking changes (including serialization changes) and add them to commit message following the conventional commit specification

zama-ai / tfhe-rs