Drop conversion to Git by default
This is just setting the default value of the feature flag introduced for #580 (closed) to
- opt-out support is fully ready
- exception for #125 is ready (technically the same as the opt-out, but will persist after the feature flag is fully dropped, so it's better to give interested Project Maintainers a single action to perform).
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information