Add OpenSUSE 12 build support once dependencies are resolved

[patrick-stephens]

Problem

OpenSUSE 12 build support was intentionally excluded due to missing C++17 support required for deduplication features and other missing dependencies.

Background

From PR #3, OpenSUSE 12 is too old for C++17 support required for deduplication and other features, so it was disabled for now.

Tasks

• Investigate feasibility of backporting C++17 compiler support for OpenSUSE 12
• Identify and resolve missing dependencies for OpenSUSE 12
• Evaluate if custom builds of required dependencies are needed (similar to SUSE 15 approach)
• Consider alternative approaches if C++17 cannot be resolved:
  • Conditional compilation to disable features requiring C++17
  • Provide builds without deduplication features for OpenSUSE 12

Acceptance Criteria

• OpenSUSE 12 builds successfully in CI
• Feature parity documented (what works vs. what doesn't)
• Add to build-config.json targets list
• Integration with existing packaging workflow

Related

• PR: feat: add OpenSuse builds and fix up container builds #3 - feat: add OpenSuse builds and fix up container builds
• Related to OpenSUSE 15 implementation in custom/packaging/distros/suse/Dockerfile