Override the entrypoint when extracting assets

When overriding the command, docker will still run the entrypoint. We
want to avoid that here - we just want to get the assets out as quickly
as possible. Otherwise maybe something important is going on when we
stop the container.

lib/kamal/commands/app/assets.rb

@@ -5,7 +5,7 @@ module Kamal::Commands::App::Assets
     combine \
       make_directory(role.asset_extracted_path),
       [ *docker(:stop, "-t 1", asset_container, "2> /dev/null"), "|| true" ],
-      docker(:run, "--name", asset_container, "--detach", "--rm", config.absolute_image, "sleep 1000000"),
+      docker(:run, "--name", asset_container, "--detach", "--rm", "--entrypoint", "sleep", config.absolute_image, "1000000"),
       docker(:cp, "-L", "#{asset_container}:#{role.asset_path}/.", role.asset_extracted_path),
       docker(:stop, "-t 1", asset_container),
       by: "&&"