Pro: we are reusing not only the uv, dtc, and qrg installation but
also the Project records (which have to be pre-fetched from the API as
extra information for processing Person records anyway).
Con: less granularity
This adds a POOLAPI variable to make the pipe commands shorter and
more readable, and removes the unused job outputs feature (originally
intended to store the git commit outcome and conditionally trigger
another workflow, but its usage was commented out because we could not
get it to work as intended).
Temporary files are written into .cache instead of /tmp (the .cache is
also something that the code from pool-publication-page may use for
its own purposes).
