Use S3FS in S3Reader (#12061)

* use s3fs

* when key=none

* use s3fs

* changelog + version bump

* tests + serialization

* changelog

* pants update

* module mappings

* add files reader to BUILD

* more BUILD

* fix schema

* give BaseReader a __modify_schema__

* dont use ModelField

* remove validators

* Support schema in BaseReader for PydanticV2

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Co-authored-by: Logan Markewich <logan.markewich@live.com>