Upgrade Lerna to 7.x or use npm workspaces instead

[EmiM]

We have to migrate lerna 6.x -> 7.x, the difference is significant, bootstrap and other commands are removed: https://lerna.js.org/docs/legacy-package-management

[EmiM]

Kacper started working on this some time ago: #1930

[holmesworcester]

Someone also suggested npm workspaces as an alternative, I think. Just noting this here.

[EmiM]

Yes, Wiktor suggested that and we considered it but lerna has some additional features that we may need.
https://stackoverflow.com/questions/64909635/is-lerna-needed-anymore-with-npm-workspaces

Upgrading lerna requires some work but also giving up using lerna requires work.