task: JSONPlayback can be tricky to test

[gmazoyer]

Component

Python SDK

Task Description

The playback is using json.dumps(payload) which produces JSON with spaces after colons (e.g., {"key": "value"}), but httpx serializes JSON without spaces (e.g., {"key":"value"}).

This can lead to difficulty while testing the JSONPlayback when trying to compare hashes. We should either use ujson which produce a whitespace free JSON or instruct json.dumps to use (',', ':') as separator.