fix(CLASP.Python): constrain uv/ruff to Python 3.8+

Stop uv from resolving ruff against the declared 2.7 floor by matching the
Quench/recls optional-deps markers and tool.uv environment limits.

Fixed failure when reading integer option value from short form (#8)

* settings

* fix: fixed failure message to be passed to `MissingValueException`

* feature: added unit-tests to exercise the observed failure

* fix: falsy default values causing `MissingValueException` for option arguments

Using a truthiness check `if given_value:` on option arguments causes
valid, falsy default values (such as `0`, `0.0`, or `False`) to be treated
as if they were missing or not set. This leads to an incorrect
`MissingValueException` being raised during command-line argument parsing.

Replacing this with an explicit `is not None` check allows falsy default
values to be correctly recognized, processed, and validated according to
their respective value types.

* 0.8.12

Boilerplate (#4)

* chore: renamed **build_egg.sh** => **build_dist.sh**

* feature: build script(s)

* core: added .gitattributes

* core: ignores

* chore: settings

* chore: boilerplate

* chore: LICENSE

* chore: updated version (patch)

* fix: corrected **setup.py**'s `packages`

* feature: added **MANIFEST.in**

* chore: Python 2.7 compatibility

* chore: added **tests/run_unittest.py**

* chore: misc. boilerplate

* feature: added GitHub Actions

* chore: updated **README.md** structure and added badges

* chore: fixes, and boilerplate

* squash-commit of 0.8.10.1

* fix

`(expected, actual)` (#7)

* chore: ensured that all appropriate unit-tests arguments are in `(expected, actual` order

* chore: canonicalised literal strings to use double-quotes throughout except where strings are well-known (per API) for which single-quotes are used

* chore: minor boilerplate updates

* fix: enabled "hidden" test function

~ `info_lines` now accepts a `None`, which is rendered as `''` (in ac…

…cordance with **CLASP.Ruby**);

~ to-bool conversion now accepts 'OFF' and 'ON';

Merged 'dev' into 'master'

Squashed commit of the following:

commit 8db7f25
Author: Matt Wilson <152443343+mwsis@users.noreply.github.com>
Date:   Sat Aug 17 17:35:28 2024 +1000

    Tidying (#1)

    * ~ settings

    * ~ vertical layout, etc.

    * ~ improved documentation markup

    * ~ improved exception message strings and contingent report strings

    * ~ updated version of run_all_unit_tests.sh

    * ~ minor fixes to example(s)

    * ~ misc tidying

~ fixing defect in option value processing

show_usage() now issues a warning message to stderr for duplicate ali…

…ases (consistent with behaviour of CLASP.Ruby)

~ fixing compatibility with Python 3's removal of long