[CI] Stop building ci_lint Docker image

[tlopex]

This is the first step in retiring the unused ci_lint Docker image.

This PR removes ci_lint from the generated Jenkins Docker image matrix so new Jenkinsfiles no longer resolve, build, or deploy that image. It also skips ci_lint in the nightly Docker image updater and teaches git_change_docker.sh to ignore the lint Docker files that will be removed later.

The actual lint Docker files are intentionally kept in this PR for compatibility with the current Jenkins PR bootstrap path. Some PR Docker jobs may still run the main-branch pipeline while reading files from the PR checkout, and that older pipeline still passes ci_lint to determine_docker_images.py during prepare. Keeping the files and the temporary docker-images.ini entry avoids failing before the updated generated Jenkinsfiles take effect.

A follow-up PR can delete docker/Dockerfile.ci_lint, docker/install/ubuntu_install_clang_format.sh, docker/lint.sh, and the README lint Docker example after this lands.

[gemini-code-assist]

Code Review

This pull request removes the ci_lint Docker image and its associated setup scripts, updating the Jenkins pipeline files and local scripts to run linting locally via pre-commit instead of inside a dedicated container. The reviewer noted that the fix parameter in the lint function in tests/scripts/ci.py is now unused and should be removed from the function signature and docstring.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.