`mcr.microsoft.com/devcontainers/base:ubuntu` points to `jammy` & major version release

[samruddhikhandale]

📢 We have released a new major version for the base-ubuntu image (ie mcr.microsoft.com/devcontainers/base).

ℹ️ Now the mcr.microsoft.com/devcontainers/base:ubuntu points to the latest LTS release (ie. jammy)

Hence, if you previously used mcr.microsoft.com/devcontainers/base:ubuntu with the hope to use the focal variant. It needs to be updated to mcr.microsoft.com/devcontainers/base:focal instead.

ℹ️ Usually, the dev configuration files reference the images by pinning to a major version (details here). In this case, the major version has bumped from 0 to 1

Dev configuration files referencing to the old image tag (ie 0-${VARIANT}) needs to be updated as below 👇

• 1-ubuntu
• 1-ubuntu22.04
• 1-ubuntu-22.04
• 1-jammy
• 1-ubuntu20.04
• 1-ubuntu-20.04
• 1-focal
• 1-ubuntu18.04
• 1-ubuntu-18.04
• 1-bionic