fix(ci): include docker-postgres-setup job in docker-unified workflow

[Masterchen09]

See also here: https://datahubspace.slack.com/archives/C02FKQAGRG9/p1727725080514819

Disclaimer: I have absolutely no idea whether this will solve the issue with the datahub-postgres-setup image in the future, I have just copied the logic for the datahub-mysql-setup image and adjusted it for the datahub-postgres-setup image...not sure why there is a separate workflow for building the datahub-postgres-setup image, however it would make sense that it should follow the same logic as the workflow for the datahub-mysql-setup image...

Someone also has to manually tag the datahub-postgres-setup:6a165a8 image with the tag datahub-postgres-setup:v0.14.1, otherwise the (now official, not only pre-release) new release for v0.14.1 will not work for those who are using a PostgreSQL database: https://hub.docker.com/layers/acryldata/datahub-postgres-setup/6a165a8/images/sha256-487aaf113b21d7656996a377a0e21cf8ac6824af282f3e72d580e403b1049ab0?context=explore

FYI @david-leifker

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