Node 20 Upgrade

### Description

Part of https://github.com/openedx/public-engineering/issues/232. See https://github.com/openedx/public-engineering/issues/267 for the general description and motivation.  Make sure to follow its recommendations for each step of the process.

```[tasklist]
- [ ] https://github.com/openedx/browserslist-config/pull/15
```