endtoend: regenerate the process plugin golden for the PostgreSQL relation seed

The seed now spells an array column as its element with the array flag,
and int2vector and oidvector columns as their own types, which the
external JSON plugin reports the same way the built-in one does.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qryf7a1doPFuCz2eGT3bCr

Author: claude