Fix deployment

[fabern]

This attempts to re-establish deployment of the book. (Tested in separate repository)

CI job previously failed because:

• R pkgs terra/sf could not be installed. Since January 2025, Ubuntu 24.04 instead of 22.04 is used for CI jobs, which made the pipeline with current R and renv-fixed packages fail. Fixing R to 4.3.2 and updating the package repository fixes this (for the moment)
• API connection to HWSD (Harmonized World Soil Database) fails occasionally. To publish the book this API connection needs to be done 4 times. It is likely that it fails at least once, preventing deployment of the book. This is currently unsolved and has just been outcommented in the book.

1. @stineb, what should we do about the last point? Currently it is simply commented out
   An alternative would be to do the rendering 1x locally and push the files from the local /_freeze folder. Upon CI run, it would only render the chapters that had changes since this freeze. This might be working until we make changes to appendix.qmd or data_variety.qmd. (Actually, this freeze might have been the reason it worked previously!?)

2. Note that the current CI pipeline might fail again, since it combines fixed and moving parts:

   • (moving) ubuntu-latest (und corresponding RSPM)
   • (moving) pandoc, quarto
   • (moving) spatial libraries (libgdal, libproj, libgeos, libudunits2, netcdf)
   • (moving) renv-version
   • (fixed) R-version
   • (fixed) R packages (in renv.lock)

   Options are to

   • fix everything to currently working setup,
   • or use latest version of all components, requiring manual updates to renv.lock