Disable publish delay

[developomp]

Flathub has a built-in 3-hour delay for a new build to hit the public repository.
Until then, it is only available in the testing repository.
This PR removes the delay, so once the build completes, it is immediately available to the users.

Related links

https://github.com/flathub/flathub/wiki/App-Maintenance#automatic-publishing-delay/
https://blogs.gnome.org/alexl/2019/02/19/changes-in-flathub-land/

[flathubbot]

Started test build 92847

[flathubbot]

Build 92847 successful
To test this build, install it from the testing repository:

flatpak install --user https://dl.flathub.org/build-repo/90575/sh.ppy.osu.flatpakref

[peppy]

Is this pretty standard practice?

[developomp]

Not sure. I decided that the change made sense because it would be odd if flatpak users have to wait an arbitrary amount of time when there appears to be no benefit to doing so.

[peppy]

Will wait for a more knowledgeable second opinion on this.

[BiteDasher]

Sometimes right after the release of a new osu! version I need to tweak something in the manifest and update some libraries, for example. I think I'll reduce the time to an hour, in case I need to do something.