Fix javascript error when an anonymous user visiting migration page (#32144)

This PR fixes javascript errors when an anonymous user visits the
migration page.
It also makes task view checking more restrictive.

The router moved from `/user/task/{id}/status` to
`/username/reponame/-/migrate/status` because it's a migrate status.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

services/context/repo.go

@@ -614,7 +614,10 @@ func RepoAssignment(ctx *Context) context.CancelFunc {
 		}
 	}
 
-	isHomeOrSettings := ctx.Link == ctx.Repo.RepoLink || ctx.Link == ctx.Repo.RepoLink+"/settings" || strings.HasPrefix(ctx.Link, ctx.Repo.RepoLink+"/settings/")
+	isHomeOrSettings := ctx.Link == ctx.Repo.RepoLink ||
+		ctx.Link == ctx.Repo.RepoLink+"/settings" ||
+		strings.HasPrefix(ctx.Link, ctx.Repo.RepoLink+"/settings/") ||
+		ctx.Link == ctx.Repo.RepoLink+"/-/migrate/status"
 
 	// Disable everything when the repo is being created
 	if ctx.Repo.Repository.IsBeingCreated() || ctx.Repo.Repository.IsBroken() {