There is!
Very recently, Safari has added support for the PRF extension. While it isn’t working perfectly for hardware keys, it’s now possible to save a passkey in Apple’s built in password manager and use it to log into the web vault passwordlessly on macOS/Safari.
Also recently, the needed PRF extension for related origins was merged. This was the blocker for bringing “login with passkey” to the browser extension.
Bitwarden will provide more details when work is in progress, but be on the lookout for updates in the not too distant future.