Drop haf submodule, use existing HAF images

Dan Notesteinrequested to merge
feature/drop-haf-submodule into develop

This MR removes the haf submodule dependency and uses pre-built HAF images from the registry instead.

Changes

  • Remove haf submodule dependency entirely
  • Use pre-built HAF Docker images from registry.gitlab.syncad.com/hive/haf:{commit}
  • Derive image tag from first 8 characters of HAF_COMMIT variable
  • Add shm_dir relocation logic for cache format compatibility
  • Fix HAF registry path in start-ci-test-environment.sh (remove /instance suffix)
  • Add COMMON_CI_REF variable for fetching common CI scripts

Benefits

  • Faster CI startup (no submodule checkout)
  • Simpler CI configuration
  • Aligns with balance_tracker pattern

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