Drop Python 3.9 support and adapt SPEC 0 standard

[No767]

Summary

As title states. Drops support for Python 3.9, and any other prep that is required for this change.

Types of changes

What types of changes does your code introduce to Rodhaj?
Put an x in the boxes that apply

• Bugfix (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)
• Documentation Update (Updates to README.md, the documentation, etc)
• Other (if none of the other choices apply)

Checklist

Put an x in the boxes that apply

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes. (if appropriate)
• All workflows (except pre-commit.ci) pass with my new changes
• This PR does not address a duplicate issue or PR

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud