fix: require pyarrow>=18.0.0 for native UUID type support

[anxkhn]

Rationale for this change

PyIceberg's PyArrow UUID handling depends on the native UUID APIs pyarrow.uuid()
and pyarrow.UuidType, but the pyarrow, pandas, duckdb, and ray extras
still pin pyarrow>=17.0.0.

• On write, PyArrowSchemaVisitor.visit_uuid returns pa.uuid()
  (pyiceberg/io/pyarrow.py:806).
• On read, _ConvertToIceberg.primitive branches on
  isinstance(primitive, pa.UuidType) (pyiceberg/io/pyarrow.py:1497).

Both pyarrow.uuid() and pyarrow.UuidType were introduced in Apache Arrow
18.0.0 (released 2024-10-28) and do not exist in 17.x. So an environment that
resolves pyarrow==17.x under the current floor raises
AttributeError: module 'pyarrow' has no attribute 'uuid' (or 'UuidType') as
soon as a UUID-typed column is written, or an Arrow schema containing a UUID is
converted back to Iceberg.

This usage was added in #2007 ("Fix UUID support") without raising the floor, and
the earlier Bump PyArrow to 18.0.0 change only moved the tested/locked version,
not the declared lower bound. This PR bumps the floor to pyarrow>=18.0.0 for the
four affected extras so the declared dependency matches what the code actually
requires. See also #1174 (Minimum required pyarrow version).

Are these changes tested?

This is a dependency-floor bump with no code change, so the real guard is CI
resolving the raised floor across the supported Python matrix; uv lock --check
confirms uv.lock stays in sync with pyproject.toml.

Locally:

• uv lock --check passes (lock in sync).
• make lint (ruff, ruff-format, mypy, license, uv-lock, ...) all pass.
• Existing UUID coverage still passes and exercises both affected code paths:
  tests/io/test_pyarrow_visitor.py (60 passed),
  tests/utils/test_schema_conversion.py -k UUID (2 passed), and the UUID cases in
  tests/test_conversions.py (2 passed). A manual round-trip
  UUIDType -> pa.uuid() -> pa.UuidType -> UUIDType runs clean.

No new test is added because there is no new code path to cover: the existing UUID
conversion tests already exercise visit_uuid and _ConvertToIceberg, and the
floor bump only makes the declared dependency honest. A heavier alternative would
be to version-gate pa.uuid()/pa.UuidType at runtime (as done for
AzureFileSystem via MIN_PYARROW_VERSION_SUPPORTING_AZURE_FS in
pyiceberg/io/pyarrow.py), but that keeps UUID unsupported on 17.x rather than
requiring the version the feature needs; happy to go that route instead if
preferred.

Are there any user-facing changes?

Yes, indirectly: the minimum supported pyarrow for the pyarrow, pandas,
duckdb, and ray extras rises from 17.0.0 to 18.0.0. This only affects
environments currently resolving pyarrow 17.x, where UUID columns are already
broken; it prevents that unsupported install rather than changing any working
behavior. (Adding the changelog label if this warrants a changelog entry - I
don't have permission to set labels as an external contributor.)