CI: add check_changed_aports_versions.py

Make sure that changed aports always have a higher version than what is currently in master. This check can be skipped with ci:skip-vercheck (in square brackets).

Related: #187 (closed)

Testing

hello-world modified, without changing the version

https://gitlab.postmarketos.org/postmarketos/pmaports/-/jobs/219129186

checking changed package versions...
- hello-world: 1-r4 (HEAD) == 1-r4 (master) [ERROR]

ERROR: Modified package(s) don't have an increased version!

hello-world modified, with lower version

https://gitlab.postmarketos.org/postmarketos/pmaports/-/jobs/219131222

checking changed package versions...
- hello-world: 1-r3 (HEAD) < 1-r4 (master) [ERROR]

ERROR: Modified package(s) don't have an increased version!

hello-world modified, with lower version and [ci:skip-vercheck]

https://gitlab.postmarketos.org/postmarketos/pmaports/-/jobs/219132839

WARNING: not checking for changed package versions ([ci:skip-vercheck])!

hello-world modified, with higher version

https://gitlab.postmarketos.org/postmarketos/pmaports/-/jobs/219133678

checking changed package versions...
- hello-world: 10-r0 (HEAD) > 1-r4 (master)
Running after script...
$ .gitlab-ci/move_logs.sh $CI_PROJECT_DIR
Job succeeded

multiple packages modified, with higher version

https://gitlab.postmarketos.org/postmarketos/pmaports/-/jobs/219134373

checking changed package versions...
- hello-world-wrapper: 1-r3 (HEAD) > 1-r2 (master)
- hello-world: 10-r0 (HEAD) > 1-r4 (master)
Running after script...
$ .gitlab-ci/move_logs.sh $CI_PROJECT_DIR
Job succeeded