Caskaydia Cove is a fork of the Cascadia Code typeface with the RFN (Reserved Font Name) removed, plus small adjustments to conform to the Google Fonts spec. The name comes from the Nerds Fonts project, which uses “Caskaydia Cove” for its patched version of Casdadia Code. The RFN prevents distributing modified versions of fonts under the names used by their upstream maintainers, so if you are looking for something like Cascadia Code that can be modified for inclusion in various font collections without a name change, this repository might be what you are looking for.
The Cascadia Code upstream project is designed by Aaron Bell and developed by the Windows Terminal team.