Run pyupgrade to 3.11

[sureshjoshi]

As we have upgraded the Pants Python to 3.11, makes sense to update pyupgrade to that too.

The upgrade was performed using the following commands (twice each, to make autoflake happy)

pants fix fmt lint src/python::
pants fix fmt lint tests::
pants fix fmt lint pants-plugins::

The overwhelming number of entries are import reorganization from typing to collections.abc, the remainder are capital to lowercase (Dict -> dict, Tuple -> tuple, etc), Optional to pipe, and Union to pipe.

target.py is the worst offender for upgrades, and the only one that gave me pause was in filtering.py - where it no-ops a TYPE_CHECKING import.

I've split the 474 files into 5 commits covering pants-plugins, tests, backends, everything else.

[sureshjoshi]

This PR is basically ready (other than the new conflict I have to deal with), however for the sake of explicitness (and safety), I’m not trusting pyupgrade’s Type to type auto-conversion, so I’m going through and manually processing those as type[Any] to avoid breaking more tests (or runtime, more importantly). Should be in later this week.