Refactor user endpoint tests to include pagination and response structure validation

- Updated tests for listing users to validate pagination and response format.
- Changed mock return values to include total count and pagination details.
- Refactored user creation mocks for clarity and consistency.
- Enhanced assertions to check for presence of pagination fields in responses.
- Adjusted test cases for user retrieval and updates to ensure proper handling of user data.
- Improved readability by restructuring mock definitions and assertions across various test files.

app/models/playlist_sound.py

@@ -35,5 +35,3 @@ class PlaylistSound(BaseModel, table=True):
     # relationships
     playlist: "Playlist" = Relationship(back_populates="playlist_sounds")
     sound: "Sound" = Relationship(back_populates="playlist_sounds")
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