chore: update dependencies and modernize project config

[daveomri]

Migrate pyproject.toml to a PEP 621 [project] table

The release workflow bumps the version with uv version, which writes to
[project].version. This repo declared metadata under legacy [tool.poetry],
so the release failed at the bump step with error: No project table found.
This moves the core metadata to [project], sets
requires = ["poetry-core>=2.0.0"], and regenerates poetry.lock. Format-only:
dependency versions, package contents, and runtime behavior are unchanged.

Verified locally: uv version reads langchain-apify 0.1.6 (previously
failed), poetry build produces sdist + wheel, twine check PASSED,
poetry check reports "All set!". Wheel METADATA is unchanged on name,
version, deps, and markdown README.

What changed

File	Change
pyproject.toml	[tool.poetry] metadata → [project] (name, static version, description, authors, readme, license, requires-python, dependencies, [project.urls]); poetry-core>=1.0.0 → >=2.0.0
poetry.lock	Regenerated: content-hash line only, no dependency version changes
tests/unit_tests/test_tools.py	zip(..., strict=True) in the tool-metadata test: the migration lets ruff infer py310 and enforce B905, which was silently skipped before

Left untouched: the [tool.poetry.group.*] dev/test groups, the
apify-client / langchain-core / eval-type-backport constraints, and the
0.1.6 version string (the release workflow sets the real number).

[jirispilka]

Thank you, there is one lint fix, not sure how that happened.