Pynamodb

What's Changed
* Fix DeprecationWarning: datetime.datetime.utcfromtimestamp() is deprecated and scheduled for removal in a future version. by shcherbin in https://github.com/pynamodb/PynamoDB/pull/1261

New Contributors
* dubli91 made their first contribution in https://github.com/pynamodb/PynamoDB/pull/1254
* shcherbin made their first contribution in https://github.com/pynamodb/PynamoDB/pull/1261

**Full Changelog**: https://github.com/pynamodb/PynamoDB/compare/6.0.1...6.0.2

What's Changed

Features:

* For failed transaction, return the underlying item in `cancellation_reasons[...].raw_item` (1226). This only applies when passing `return_values=ALL_OLD`.

Fixes:

* Fixing (1242) regression to the `extra_headers` feature. These headers are intended for proxies that strip them, so they should be excluded from the AWS signature.

**Full Changelog**: https://github.com/pynamodb/PynamoDB/compare/6.0.0...6.0.1

This is a major release with breaking changes.

Please read the [release notes](https://pynamodb.readthedocs.io/en/latest/release_notes.html#v6-0-0) carefully for a full list of changes.

What's Changed
* Fix compatibility with botocore 1.33.2 by ikonst in https://github.com/pynamodb/PynamoDB/pull/1206


**Full Changelog**: https://github.com/pynamodb/PynamoDB/compare/5.5.0...5.5.1

What's Changed
* Add 'add_version_condition' arg by ikonst in https://github.com/pynamodb/PynamoDB/pull/1177


**Full Changelog**: https://github.com/pynamodb/PynamoDB/compare/5.4.1...5.5.0

What's Changed
* Use model's AWS credentials in threads by atsuoishimoto

**Full Changelog**: https://github.com/pynamodb/PynamoDB/compare/5.4.0...5.4.1