cli: set default completion

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

commands/prune.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/docker/buildx/builder"
+	"github.com/docker/buildx/util/cobrautil/completion"
 	"github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
 	"github.com/docker/cli/opts"
@@ -139,6 +140,7 @@ func pruneCmd(dockerCli command.Cli, rootOpts *rootOptions) *cobra.Command {
 			options.builder = rootOpts.builder
 			return runPrune(dockerCli, options)
 		},
+		ValidArgsFunction: completion.Disable,
 	}
 
 	flags := cmd.Flags()