devel/developer-setup: Some updates

I followed the steps from the developer setup in an empty debian bookworm container but could no longer install all SWH components.

This MR updates the developer setup in order to get a successful installation of SWH development environment.

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Why did you remove the part about yarn being required only when working on Web Applications? Is it because of swh-search?

Yes otherwise calling ./bin/install fails without yarn installed.

approved this merge request

merged manually