Add missing HISTORY entries for 0.10.4
## Bug fixes
* Error out when applying `QueryCondition` to dense arrays; this feature will be implemented in TileDB Embedded 2.5 [#753](https://github.com/TileDB-Inc/TileDB-Py/pull/753)
* Ensure that indexer, multi-indexer, and df return the same results when applying `QueryCondition` [#753](https://github.com/TileDB-Inc/TileDB-Py/pull/753)
+* Fix error when using .df with PyArrow 6 due to incorrect metadata field in exported schema [#764](https://github.com/TileDB-Inc/TileDB-Py/pull/764)
+* Fix [#755](https://github.com/TileDB-Inc/TileDB-Py/issues/755): `from_pandas` to correctly round-trip unnamed Index [#761](https://github.com/TileDB-Inc/TileDB-Py/pull/761)
+* Fix .df indexer bug with empty result set [#744](https://github.com/TileDB-Inc/TileDB-Py/pull/744)
## API Changes
* Close the `PyFragmentInfo` object in the `FragmentInfoList` constructor to reflect changes in the `FragmentInfo` API in TileDB Embedded 2.5 [#752](https://github.com/TileDB-Inc/TileDB-Py/pull/752)
