dev_install.md should mention yarn 4

[fm3]

context: https://scm.slack.com/archives/C5AKLAV0B/p1726041769346569

how to install yarn 4 on ubuntu, MacOS?

[hotzenklotz]

Yarn get's installed by NodeJS (or rather the NodeJS core package corepack) automatically. See: https://github.com/scalableminds/webknossos/blob/master/DEV_INSTALL.md#nodejs--yarn

There are no other install steps required.

[fm3]

Ah I see, thanks! I’ll have a look at how to do that exactly for ubuntu, and add that in the Ubuntu block. Maybe you could do the same for the MacOS block? (Or is it already included?)