The MariaDB job is named 'Python Unit Tests', and 'Python Unit Tests (1..4)' are the
required status checks on develop. Naming the Postgres matrix job the same made its
checks report under those required contexts, effectively gating every (labelled) PR on
Postgres. Rename it to 'Postgres Unit Tests' so its contexts are distinct and the
workflow stays non-required until we deliberately add it to branch protection.
Bring the Server (Postgres) workflow in line with Server (MariaDB) internals while
keeping it opt-in for now: pull_request runs still require the 'postgres' label, but the
job now uses the full 4-container matrix (was 1), adds the nightly schedule /
workflow_dispatch / repository_dispatch triggers (which always run), and uploads
coverage. Builds ERPNext against frappe `develop` (PostgreSQL query-builder/ORM support
is merged there), so no fork override is needed.
The ERPNext server suite now passes on PostgreSQL and MariaDB from a single codebase;
flipping this to run on every PR / become a required check is a later, separate step.
