Avoid rebuilding the docker images

• Jobs with running the tests:

  • clang-tidy
  • clang-analyzer
  • debian11 (-> debian12)
  • debian11-no-jpeg (-> debian12-no-jpeg)
  • debian10 (-> debian11)
  • ubuntu-20.04-jpeg9
  • ubuntu-20.04
  • sanitizer
  • coverage

• Just compile jobs:

  • abi-api-compliance-check
  • cmake-with-locations-and-min-versions
  • alpine:3.15

Dockerfiles:

• cmake-with-locations-and-min-versions

• alpine:3.15

• ubuntu-20.04-jpeg9

• Fix commits and commit messages

• Revise Testing.md, add script documentation to update the scripts submodule in all ci repos

• Nicify git ci repos

• Nicify scripts repo

• Rebase against main, add cmake 3.18 to docker images where required

Close #1069 (closed)

Close #1131 (closed)

Close #771 (closed)