Enable pyupgrade

[ulgens]

Change Summary

Enables pyupgrade rule set in ruff config.

https://docs.astral.sh/ruff/rules/#pyupgrade-up
https://github.com/asottile/pyupgrade

A tool (and pre-commit hook) to automatically upgrade syntax for newer versions of the language.

Helps to keep the code modern.

Depends on:

• Specify supported Python versions via trove classifiers #111

PR Checklist

• I have read and signed the Contributor License Agreement.

[tharropoulos]

The reason for most of the changes here was that this package supported versions of 3.9 onwards.

There are numerous changes that rely on PEP 695 (type keyword) as well as a number of union changes that use the pipe symbol.

The pipe ones should be fine as long as we deprecate 3.9 usage.

[tharropoulos]

Inheriting from object should be left out, that's for sure

[ulgens]

The reason for most of the changes here was that this package supported versions of 3.9 onwards.

To clarify, that's the reason for all of the changes. Excluding the trove update commit (I will rebase the branch when #111 is merged), the only changes are ruff config update to enable pyupgrade and fixes applied by pyupgrade.

[tharropoulos]

Wasn't type introduced in 3.12 though?

[ulgens]

@tharropoulos

• The pipe (or) changes are coming from this rule: https://docs.astral.sh/ruff/rules/non-pep604-annotation-union/ It says it's for py310-plus, I'll check why it's applied.
• type changes are coming https://docs.astral.sh/ruff/rules/non-pep585-annotation/. It's based on https://peps.python.org/pep-0585/, which was targeting Python 3.9