ExportReplay
This was already handled in ReplayDownloadButton (https://github.com/ppy/osu/blob/98efff0bd61ea6cc5d6a884aeda1614d81592b9d/osu.Game/Screens/Ranking/ReplayDownloadButton.cs#L114-L115) but seemingly missed for SaveFailedScoreButton
FireAndForget
Task.Run
Defaults to `F2` aka stable.
Previously was relying on whether `SaveReplay` returns null, but since I've changed it to use the standard "prepare score for import" path, the button has to check for local availability after import since that path doesn't return null on fail.
removed `ShakeContainer`
Most borrowed from `ReplayDownloadButton`
Let saveReplay async but still void Make failed score's rank = F