chore(deps): Remove OpenSSL 1.1.1 fallback, require OpenSSL 3.0+

[kcenon]

What

Remove OpenSSL 1.1.1 fallback support and enforce OpenSSL 3.0+ as the minimum required version for PostgreSQL SSL connections and other encrypted database transports.

Why

• Security risk: OpenSSL 1.1.1 reached End of Life (EOL) on September 11, 2023. Database connection encryption with an EOL library is a critical vulnerability.
• SOUP compliance: For safety-critical systems (IEC 62304), using EOL cryptographic libraries in data transport is a high-risk finding requiring immediate mitigation.
• Consistency: logger_system and network_system are also migrating to OpenSSL 3.0+ only. Ecosystem-wide alignment reduces testing complexity.
• PostgreSQL compatibility: PostgreSQL 16+ recommends OpenSSL 3.x for SSL connections.

Where

• CMakeLists.txt or cmake/FindSystemDependency.cmake: OpenSSL detection
• database/CMakeLists.txt: PostgreSQL backend SSL linkage
• scripts/dependency.sh: Platform dependency installation
• CI/CD workflows

How

1. Update OpenSSL version requirement to 3.0.0 minimum
2. Remove any OpenSSL 1.1.x conditional code paths
3. Update scripts/dependency.sh to install OpenSSL 3.x packages
4. Verify PostgreSQL SSL connections work with OpenSSL 3.x
5. Update README prerequisites

Acceptance Criteria

• OpenSSL 3.0.0+ enforced at configure time
• All OpenSSL 1.1.x fallback code removed
• PostgreSQL SSL connection tests pass
• scripts/dependency.sh installs OpenSSL 3.x
• CI passes on all platforms

[kcenon]

Implementation PR: #389