fix: handle zero max_items_evaluated in DynamoDB read_items

[hsusul]

Feature or Bugfix

• Bugfix

Detail

Fixes an issue in awswrangler.dynamodb.read_items where setting max_items_evaluated=0 was evaluated as a falsey truthiness check (if max_items_evaluated: and if limit:) rather than an explicit is not None check.

This resulted in two bugs when max_items_evaluated=0 was provided:

1. read_items raised exceptions.InvalidArgumentCombination stating that at least one read argument (like max_items_evaluated) must be provided, even though max_items_evaluated was explicitly passed.
2. If allow_full_scan=True was also provided alongside max_items_evaluated=0, max_items_evaluated=0 was ignored and all items in the DynamoDB table were scanned/queried without any limit.

Changes:

• Update max_items_evaluated argument validation in read_items() and _read_items() to check is not None.
• For max_items_evaluated=0, return an empty DataFrame (or empty list/iterator based on as_dataframe and chunked arguments) directly without executing unnecessary network/scan requests or violating botocore parameter validation limits.
• Raise InvalidArgumentValue if max_items_evaluated < 0.
• Add regression tests in tests/unit/test_moto.py.

Relates

• N/A

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.