test: psycopg vs asyncpg performance

[matthiasschaub]

Description

Goal is to remove one of the two database libraries in use.

Corresponding issue

Closes #746

New or changed dependencies

Checklist

• I have ensured my branch is mergeable with main (e.g. through git rebase main if necessary)
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• I have added sufficient unit and integration tests
• I have added new Hurl regression tests and checked all existing tests
• I have updated the CHANGELOG.md

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