Container image updates

[chreman]

Backend container image upgrades

Moves all backend containers off end-of-life base images and runtimes, with no change to pipeline output.

Changes

• Python services (api, persistence, orcid): python:3.9 → python:3.12-slim. The PyOrcid fork now allows current urllib3.
• R workers (pubmed, base, openaire, dataprocessing): Ubuntu 18.04/20.04 with R 3.6 → rocker/r-ver:4.4.2, the same version metrics already ran. Packages come as binaries from a dated snapshot, so the images need no compiler. Unused dependencies were removed.
• metrics: no major upgrade needed, but aligned with the same build approach
• Redis: 6.0 → 8.10
• Build hygiene: a single server/.dockerignore keeps tests, caches, local R/Python state and secrets out of the images.
• Dev/test images: PHP 8.2, Python 3.12, composer 2.8, RStudio on R 4.4.2. phpcs is now a composer dev dependency, and the PHP 8.0 test service was removed.
• Compatibility fixes for issues found in testing: pandas date parsing, a layout fallback in the ordination step, a scikit-learn topic-model setting, a forked R package, and the multi-language filter in BASE search (R data handling).