Bug: `git-opfs` demo doesn't work in Safari

I tried opening the git-opfs demo in Safari and got a runtime error: DataCloneError: The object can not be cloned.

According to MDN, Safari supports OPFS so I'd expect this example to work.

Note: The demo works as expected in Chrome.

Steps to reproduce

1. Clone the memfs repository
2. Install dependencies (yarn)
3. Run the git-opfs demo (yarn demo:git-opfs)
4. Open https://localhost:9876 in Safari (I needed to bypass the https security risk warning)

Versions

• memfs: 4.6.0
• Safari: Version 17.1 (19616.2.9.11.7)
• macOS: Sonoma 14.1