Update CI after merge from trunk

Introduce a new file .ispras.gitlab-ci.yml. Inline build/gitlab-ci.yml and .gitlab-ci.yml in it. Shrink result, remove jobs for JDK other than JDK17.

Remove dependencies key in favor of needs (needs implies dependencies and they have to be equal if both are present).

Move build-dependencies into build stage. Split checks into source-checks and binary-checks. Move build-tar into deploy stage. Add regression stage for our regression (integration) tests.

Change Dockerfile from JDK11 to JDK17. Move jobs to add benchmarks and BenchExec into JDK17 image and generate and run the tests from .gitlab-ci.yml and build/gitlab-ci.yml to this new file. Restore those as on trunk.