cmd: update the final message in osbuild-upload-pulp-ostree

Since the UploadAndDistributeCommit() function now waits for all tasks
to finish, update the wording of the final message to indicate that the
commit is available.

cmd/osbuild-upload-pulp-ostree/main.go

@@ -30,5 +30,5 @@ func main() {
 	repoURL, err := client.UploadAndDistributeCommit(filename, repository, basePath)
 	check(err)
 
-	fmt.Printf("The commit will be available in the repository at %s\n", repoURL)
+	fmt.Printf("The commit is available in the repository at %s\n", repoURL)
 }