Improved and simplified building docker images

[jesper-friis]

Description

Improved and simplified building docker images.

• fixed and updated the scripts for testing docker images locally
• factored out the generation of dockerfiles into a separate script that is reused both by the CI/CD and the testing script

Motivation for this PR: Simplify debugging failures when docker images are built, specifically the segfault problem for manylinux2014_i686 on Python 3.12. Improved maintainability.

Type of change

• Bug fix & code cleanup
• New feature
• Documentation update
• Test update

Checklist for the reviewer

This checklist should be used as a help for the reviewer.

• Is the change limited to one issue?
• Does this PR close the issue?
• Is the code easy to read and understand?
• Do all new feature have an accompanying new test?
• Has the documentation been updated as necessary?

[francescalb]

Are we not using the templates anymore? The, why are the files kept?

[francescalb]

Looks OK.

[jesper-friis]

Are we not using the templates anymore? The, why are the files kept?

The templates are still used via the new gen_dockerfile.sh script. This script is in turn used by the CI/CD and the run_cibuildwheel.sh script.