bump alpine linux to 3.19

[dklimpel]

Checklist

• make test-all (UNIX) passes. CI will also test this
• unit and/or integration tests are included (if applicable)
• documentation is changed or added (if applicable)

Description of change

Bump Alpine Linux in integration test.

[aelsabbahy]

There's some logic to publish the docker images with a checksum to speed up future CI builds. Basically, CI will download the built image instead of rebuilding it.

I wonder if those would perform faster in ghcr when this is all running as GitHub actions. 🤔

[dklimpel]

I saw the logic with the checksums. It can stay and will certainly speed things up in the future and prevent unnecessary docker builds. I can update the checksum, but not the container image on docker hub.

I see two options. Either live with a slow pipeline and update the containers and checksums at the end of all image updates.

Or first implement the new pipeline to build the containers via ghcr (or docker hub).

• Build own docker images for integration tests #901
  (without changing the pipeline/scripts to use the new images)

[aelsabbahy]

Agree with your assessment,

1. I'll manually update the image + checksum for now. The logic just falls back to slower builds, so nothing is broken.
2. When pipelines are ready, they will be responsible for updating the images after successful CI. This way whenever we make image changes, they're slow at first, but speed up once CI passes in master branch.