v0.21.0-beta.3

What's Changed

New Features 🎉

• feat(java): support drop columns for dataset by @yanghua in #3237
• feat(java): expose uri method for Dataset instance by @yanghua in #3231

Bug Fixes 🐛

• fix: remove overzealous warning by @westonpace in #3239
• fix: correctly copy null buffer when making deep copy by @westonpace in #3238

Full Changelog: v0.21.0-beta.2...v0.21.0-beta.3