Evaluate whether a devcontainer image prebuild would improve reliability

[StevenMaude]

If we use a prebuilt image in the research-template dev container configuration, might that make launching codespaces faster and more reliable? If so, we may want to switch to such a prebuilt image.

We wouldn't then, for example, be relying on access to Ubuntu services at codespace startup, for the docker-in-docker-installation.

As discussed in this Slack thread.

Relevant dev containers documentation:

• https://containers.dev/guide/prebuild
• https://containers.dev/implementors/reference/#prebuilding