Create update to container to copy latest 2.9.x composer to the image over the one supplied by the microsoft container

[shaundrong]

devcontainer-drupal/Dockerfile

Lines 1 to 2 in 49cb69a

	FROM mcr.microsoft.com/devcontainers/php:8.3

adding as a note so I can return to it after our Drupal security patch day.

• https://getcomposer.org/doc/00-intro.md#docker-image
• https://hub.docker.com/r/composer/composer/tags
• https://docs.docker.com/build/building/multi-stage/

I feel like I can just add the copy command to the current build stage to copy in composer, but will test locally before making a PR, if not I will create a new stage to add it in.