ports-mgmt/zig2tuple: Update to g20260706

Rewrites the ZON dependency parsing with std.zig.Ast + Zoir.

Other changes:

• Fixed formatUrl from trimming git+ commit hashes by 7 chars. Hashes are now at 40 chars and removes any possible commit ambiguity.
• Drop the tarball-extension allowlist.
• Dedupe packages that appear under multiple mirror URLs.
• Report malformed ZON to stderr instead of silently skipping it.

Approved by: arrowd (co-mentor)