celestia-app v0.13.0-rc2

What's Changed

• chore: bump NMT to v0.15.0 by @rootulp in https://github.com/celestiaorg/celestia-app/pull/1580

Full Changelog: https://github.com/celestiaorg/celestia-app/compare/v0.13.0-rc1...v0.13.0-rc2