bookworm-multipython: Bump nodejs to 20 and install yarn with corepack
nodejs 18 is close to EOL and some swh-web dependencies bump minimal required nodejs version to 20.
Prefer to install yarn using the corepack tool instead of debian packages.
nodejs 18 is close to EOL and some swh-web dependencies bump minimal required nodejs version to 20.
Prefer to install yarn using the corepack tool instead of debian packages.