Allow package cleanup from admin page (#25307)

Until now expired package data gets deleted daily by a cronjob. The
admin page shows the size of all packages and the size of unreferenced
data. The users (#25035, #20631) expect the deletion of this data if
they run the cronjob from the admin page but the job only deletes data
older than 24h.

This PR adds a new button which deletes all expired data.

![grafik](https://github.com/go-gitea/gitea/assets/1666336/b3e35d73-9496-4fa7-a20c-e5d30b1f6850)

---------

Co-authored-by: silverwind <me@silverwind.io>

routers/web/web.go

@@ -597,6 +597,7 @@ func registerRoutes(m *web.Route) {
 		m.Group("/packages", func() {
 			m.Get("", admin.Packages)
 			m.Post("/delete", admin.DeletePackageVersion)
+			m.Post("/cleanup", admin.CleanupExpiredData)
 		}, packagesEnabled)
 
 		m.Group("/hooks", func() {