Reorder classifiers and update Python requirement syntax in pyproject.toml

[chrimaho]

This pull request updates the pyproject.toml file to enhance metadata clarity and correct the Python version requirement syntax. The most important changes include reorganizing and expanding the classifiers section and adjusting the requires-python field.

Metadata improvements:

• Reorganized and expanded the classifiers section to include additional topics such as Testing :: Unit and Utilities, improving the discoverability and categorization of the project.

Syntax correction:

• Updated the requires-python field from ">3.9,<4.0" to ">=3.9,<4.0" to align with standard version specification syntax.

[Copilot]

Pull Request Overview

This PR improves project metadata by reorganizing the classifiers and correcting the Python version requirement syntax.

• Reorganized the classifiers section to enhance discoverability by adding topics such as "Testing :: Software Development :: Testing :: Unit" and "Utilities".
• Updated the requires-python field syntax to ">=3.9,<4.0" to properly include Python 3.9 as a valid version.