Added Python 3.14

[danielmorell]

Description of the change

This PR...

• Adds testing and support for Python 3.14. All the tests passed locally for Python 3.14.
• Removed testing / support for Python 3.7 and 3.8 since they have reached end of life.
• Updates the versions of frameworks that we test against / support.

Type of change

• Maintenance

Related issues

None

Checklists

Development

• Lint rules pass locally
• The code changed/added as part of this pull request has been covered with tests
• All tests related to the changed code pass in development

Code review

• This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
• "Ready for review" label attached to the PR and reviewers assigned
• Issue from task tracker has a link to this pull request
• Changes have been reviewed by at least one other engineer