Remove invalid images that don't actually build / exist

[m-rph]

Context: CodeBuild during batch building generates images that are impossible to build, e.g. alpine 3.13 with python 3.10.
Task: Remove invalid alpine combinations. For reference see how this is done for node-js.

NB: This task will be semi reverted once we have a more modern bootstrapping approach for the python environment and we can use a build matrix once more but without relying on the OS to provide the runtime.