Add guard to disable pyarrow features in older pyarrow versions

[agoose77]

Version of Awkward Array

main

Description and code to reproduce

As discussed in meeting.

[jpivarski]

If it takes long enough to get around to this, we might instead just require a higher minimal pyarrow version.

The testing suite is a good source of information about our minimal Arrow version. Right now, it looks like it's 13:

% fgrep -r 'pyarrow.__version' tests

tests/test_2650_arrow_array_highlevel.py:    parse_version(pyarrow.__version__) < parse_version("12.0.0"),
tests/test_2757_attrs_metadata.py:    if packaging.version.Version(pyarrow.__version__) < packaging.version.Version("13"):

But in the codebase, we only require 7:

% fgrep -r 'pyarrow.__version' src/awkward/

src/awkward/_connect/pyarrow.py:    if parse_version(pyarrow.__version__) < parse_version("7.0.0"):

If anything, it should happen at a minor version bump; see https://github.com/scikit-hep/awkward/wiki#api-breaking-changes-after-20

Check the Arrow releases page to see the temporal constraint that a new Arrow release would impose. Version 13 = August 2023 is a bit too recent to do this now. If this is being implemented before August 2024, then there should be a guard for the ak.str.* functions and a minimal version for everything else.