fix: watch with no query raises RuntimeError under PEP 479

[VXNCXNX]

Description

watch with no query raises RuntimeError instead of printing its usage.

$ litecli -e 'watch' :memory:
generator raised StopIteration

Same for watch -c and watch 3, the two other ways to reach the end of the arguments without a statement.

watch_query is a generator, and it ends four of its paths with raise StopIteration. Under PEP 479, which is mandatory from Python 3.7 and this project requires 3.10+, a StopIteration raised inside a generator is converted to RuntimeError rather than ending iteration. So the generator yields the usage tuple and then immediately blows up.

Replacing each with a bare return is the documented fix, and it is what the surrounding code already does implicitly by falling off the end.

After, the generator yields the usage row and stops:

$ python -c "from litecli.packages.special.iocommands import watch_query; print(len(list(watch_query(''))))"
1

and the CLI exits cleanly.

Two of the four are worth calling out because they are not just the no-argument case:

• the "Wise choice!" branch, reached by answering no to a destructive-query confirmation inside watch
• the KeyboardInterrupt handler, so Ctrl-C during a watch loop hits the same RuntimeError rather than stopping

Checklist

• I've added this contribution to the CHANGELOG.md file.

Testing

test_watch_without_a_query_prints_usage in tests/test_special_iocommands.py, parametrised over watch, watch -c and watch 3, asserting the usage tuple is the only result.

Reverting the source fails all three:

E   RuntimeError: generator raised StopIteration
FAILED tests/test_special_iocommands.py::test_watch_without_a_query_prints_usage[watch]
FAILED ...[watch -c]
FAILED ...[watch 3]

pytest is 231 passed, 2 skipped, 1 xfailed, 1 xpassed. CI's pinned ruff==0.11.5 reports All checks passed and 38 files already formatted.

One note in case you run a newer ruff locally: latest ruff reports 195 errors on a clean checkout here, including the PLR1708 rule that flags exactly these four lines. Since CI pins 0.11.5 I did not touch anything else it complains about.

Disclosure: written with AI assistance (Claude Code). I reproduced the error, ran the before and after and the revert check myself.