Adds support to python 3.13

[jairhenrique]

Describe the change
Run tests on python 3.13

PR Checklist

• Change is covered with tests
• CHANGELOG.md is updated if needed

[amureki]

Let's take out the unrelated changes to a separate PR and keep it to the Python update. 🙏

[berinhard]

Thanks for the contribution. As @amureki suggested, I'd alsobe in favor of splitting the Python3.13 support from CI improvemnts/refactorings.

[amureki]

@jairhenrique I took a liberty to amend a small patch to the test matrix. Sorry that the process there is not transparent, we'd try to improve it.
Nevertheless, many thanks for the contribution!