chore: update apt pinning for checkit-tiff-upcoming, add iccmax package pinning, remove pinning for libtiff-tools package

fix: set correct Systemd Targets to make sure that validation services only start after NFS shares are available

fix: replace suite for custom repo by ansible_distribution_release fact, because ansible_lsb.* might not be universally available (especially in containers)

Resolve "wrong use of systemd templates for validation cleanup service"

Closes #1

See merge request !4

fix: move back to local /tmp/ filesystem, because Path::Tiny has issues with creating temp files on NFS shares