docs: Add BSD 2-Clause as accepted extension license (#48363)

Release Notes:

- N/A

docs/src/extensions/developing-extensions.md

@@ -115,6 +115,7 @@ As of October 1st, 2025, extension repositories must include a license.
 The following licenses are accepted:
 
 - [Apache 2.0](https://www.apache.org/licenses/LICENSE-2.0)
+- [BSD 2-Clause](https://opensource.org/license/bsd-2-clause)
 - [BSD 3-Clause](https://opensource.org/license/bsd-3-clause)
 - [GNU GPLv3](https://www.gnu.org/licenses/gpl-3.0.en.html)
 - [GNU LGPLv3](https://www.gnu.org/licenses/lgpl-3.0.en.html)