Dockerfile and installation updates

[david-yz-liu]

This pull request makes a few different updates to the Dockerfile configuration and installation scripts.

Tester-specific updates

1. Fixed the installation of ghcup for the Haskell tester (the installation was failing due to missing system packages). This ensures that stack is correctly installed system-wide; I removed the unnecessary PATH updates in the Haskell tester files.
2. Improved Haskell installation:
   • Correctly pass in environment variables to ghcup to prevent a default ghc being installed by ghcup (now the only ghc versions that should be installed are the system version with apt-get install ghc and any additional ghc versions installed by stack)
   • Run a stack update before stack build in the Haskell tester setup.py::install function. This improves the runtime of the first subsequent stack build call, which happens when a new Haskell test environment is created.
3. Refactored the R installation to include the tidyverse installation steps in the requirements.system file rather than the Dockerfile.

General updates

1. Improved the robustness of the installation process:
   • Added set -euxo pipeline to each script to ensure failed installation steps are correctly reported and all steps are echoed
   • Added logging statements to Python install scripts
2. Resolved a Dockerfile warning about passing arguments to CMD.
3. Improved Dockerfile caching by adding --mount arguments to RUN commands; reordering steps; and adding an explicit COPY for the requirements.system files to prevent cache invalidation for the installation step caused by modifying other files in the repository.