Gaffer Build Environment 3.0.0

• CI :
  • Container image is now built with podman rather than docker.
  • Container image is built with --squash-all in order to reduce overall container size.
  • References to docker.pkg.github.com have been changed to ghcr.io.
• Dockerfile :
  • Changed base image to aswf/ci-base:2023.2, changes from this image include :
    • Builds are now performed on Rocky 8.8 with glibc 2.28.
    • Updated GCC to 11.2.1.
    • Updated Python to 3.10.11.
  • Removed installation of the following packages as they are provided by the ci-base image :
    • cmake3, git, patch, doxygen.
    • bzip2-devel, zlib-devel.
    • libX11-devel, mesa-libGL-devel, mesa-libGLU-devel, libXmu-devel, libXi-devel.
    • flex, bison.
    • xkeyboard-config, fontconfig-devel, libxkbcommon-x11-devel.
    • xcb-util-renderutil-devel, xcb-util-wm-devel, xcb-util-devel, xcb-util-image-devel, xcb-util-keysyms-devel.
    • xorg-x11-server-Xvfb.
  • Removed installation of nasm as yasm is provided by the ci-base image.
  • Removed installation of lz4 and lz4-devel as we no longer build Appleseed.
  • Updated inkscape to 1.3.2.
  • Updated scons to 4.6.0.
  • Set WORKDIR to /.
  • Set OPTIX_ROOT_DIR environment variable.
  • Added GAFFER_BUILD_ENVIRONMENT="gcc11" environment variable.
  • Fixed sphinx incompatibility with automatically installed dependencies by installing specific versions of sphinxcontrib packages.
  • Removed unnecessary packages provided by the ci-base image to reduce container size :
    • cuda-nsight-compute-11-8.x86_64, libcublas-devel-11-8-11.11.3.6-1.x86_64, sonar-scanner-4.8.0.2856-linux, libcublas-11-8, libnccl, libnccl-devel, libnpp-11-8, libnpp-devel-11-8, cuda-cupti-11-8 and various intermediate installation files.