install this package for testing

[Borda]

Description

This PR removes the additional Conda environment file that was previously used for CI setup. Instead, the CI now installs the package directly, relying on its declared dependencies.

Why this is beneficial

• Single Source of Truth: Ensures that tests run against the same dependencies declared by the package itself.
• Reduced Maintenance: No need to maintain a separate environment file in sync with the package dependencies.
• Simpler CI Workflow: Streamlines the setup process by reducing duplication and potential drift between test and runtime environments.

[Borda]

seems like I may need to revert #358 as some tests were not passing...

[Borda]

could you pls have a look @amva13 🙏