Added explicit package update/upgrade step to patch CVE-2025-58183, CVE-2025-61726, CVE-2025-61728, and CVE-2025-61729 in Go stdlib components from Alpine Linux packages (likely LLVM or transitive dependencies). The fix ensures all base image packages are up-to-date before pgvector build, capturing any security patches released for Alpine components. Fixes #181 Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>