test: Write tests for stac_cli

[divyanshub024]

Currently, the stac_cli package lacks comprehensive unit tests. We should write tests to ensure its reliability and to catch regressions early when adding new features or refactoring.

Tasks

• Set up the testing infrastructure for stac_cli
• Write tests for core CLI commands
• Ensure tests run successfully in the CI pipeline

[Pratikdate]

Hi! I’d like to contribute to this issue.

I can help set up a proper testing structure for the stac_cli package and add unit tests for the core CLI commands to improve reliability and prevent regressions.

[Pratikdate]

#472