Upgrade eslint and typescript-eslint

[alcuadrado]

A new version of eslint (9.0.0) has been released some time ago, which we couldn't migrate into because typescript-eslint was incompatible.

Now, typescript-eslint 8.0.0 has been released that supports it, so we should migrate while v-next is small/simple.

The main advantage of migrating is that typescript-eslint now works better with node:test, allowing us to use no-floating-promise in our tests, without having tons of false-positives because of describe and it returning promises.

The only real blockers that may be present are the third-party plugins that we use:

• eslint-config-prettier
• eslint-import-resolver-typescript
• eslint-plugin-import
• eslint-plugin-no-only-tests