23.8.11 Reuse unchanged images

[MyroTk]

Changelog category (leave one):

• Build/Testing/Packaging Improvement

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

• Docker images used for the pipeline are built on opened or re-opened pull requests, during release or prelease, or when the related dockerfiles are updated.
• Pull request runs use <PR number> docker image tag. Release and prerelease use 0-<commit sha>