Update Flow to 0.261 (#34255)

- 0.261 required to pull out a constant to preserve refinement
- 0.259 needed some updated suppressions for hacky stuff

DiffTrain build for [d73b6f111057e09b9886e8edd2bc70fa56229489](https://github.com/facebook/react/commit/d73b6f111057e09b9886e8edd2bc70fa56229489)