Add Python 3.11 unit tests to CI

Before raising this MR, consider whether the following are required, and complete if so:

• Unit tests
• Metrics
• Documentation update(s)

If not required, please explain in brief why not.

Description

This request aims to add unit tests for Python 3.11 to the CI, and fix various linting issues.

Changes proposed in this merge request:

• Add unit test stage for Python 3.11 to CI
• Update tox interpreter list to include Python 3.10 and 3.11
• Update exception handling to avoid use of 'raise Exception', by using more specific exceptions
• Fixes to various linting issues - (use-dict-literal), (superfluous-parens)

Validation

n/a

Issues addressed

n/a