The "Element Public Roadmap" isn't public

**Describe the bug**
The "Element Public Roadmap" isn't public

**To Reproduce**
Steps to reproduce the behavior:
1. Go to [the repository](https://github.com/element-hq/roadmap)
2. Log out of GitHub
3. Click on the `Element Public Roadmap` link there ([this link](https://github.com/vector-im/roadmap/projects/1))
4. See GitHub 404 error

**Expected behavior**
I see the Element Public Roadmap
