Fix/php 8.2 deprecation warnings in v0.4.

[Floris-ll]

Issue link

https://app.asana.com/0/0/1207063286450602/f https://app.asana.com/0/0/1207063286450604/f

Description

How Has This Been Tested?

Checked on KPS if the deprectation warnings were gone. This doesn't change anything about the functionality of clarkson-core.

Screenshots (if appropriate):

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.