Formatting inconsistencies

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the issue has not already been raised

Issue

I think our current ESLint config is not deterministic enough.

I've seen several people, including myself, push stylistic changes that were accepted. Could we add a formatter to avoid this?

Also, there are new formatter/linter very fast tools, such as Biome: https://github.com/biomejs/biome

Worth thinking about it.