Backport of 'Set GITLAB_BIN_DIR for Duo CLI and bump workflow image to v0.0.23' into 19.4

What does this MR do and why?

Backports !261515 (merged) to 19.4 so that remote flows run Duo CLI 9.30.0. That release stops loading workspace MCP configuration (.gitlab/duo/mcp.json) for Rails-delivered flow runs: gitlab-org/editor-extensions/gitlab-lsp!4412 (merged).

• The default workflow image moves from v0.0.15 to v0.0.23, and DUO_CLI_VERSION from 9.21.0 to 9.30.0.
• GITLAB_BIN_DIR=/tmp/gitlab-bin is added to the sandbox job variables and refreshed on resume. CLI 9.29.0 and later extract the bundled rg to $HOME/.cache without it, which is read-only in the sandbox, so find_files would fail.

The incident reverts (!261482 (merged) and !261473 (merged)) are not included: 19.4 never had v0.0.22 or 9.29.0.

The cherry-pick needed conflict resolution because this branch predates the nono sandbox and some spec refactors. Two specs are adapted: the sandbox pass-through spec asserts on the env -i flags instead of running the generated script, and the resume spec defines its own previous build.

Compatibility notes

Checked against 19.4: the CLI invocation, env vars, GraphQL fields and SRT wrapper are unchanged. CLI 9.30.0 was also run against a 19.4.2 instance without schema errors. Things that change for some setups:

• Instances that mirror the default image need workflow-generic-image:v0.0.23 in their registry. Instances that pin a full image reference are unaffected, but keep their bundled CLI.
• Images that already contain duo skip the install and keep their CLI version.
• CLI 9.29.0 and later only extract rg into a directory whose parents are sticky or private. A non-sticky /tmp, such as a Kubernetes emptyDir mounted at /tmp, loses find_files and grep. The same applies on master.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• This MR is backporting a bug fix, documentation update, or spec fix, previously merged in the default branch.
• The MR that fixed the bug on the default branch has been deployed to GitLab.com (not applicable for documentation or spec changes).
• The MR title is descriptive (e.g. "Backport of 'title of default branch MR'"). This is important, since the title will be copied to the patch blog post.
• Required labels have been applied to this merge request
  • severity label and bug subtype labels (if applicable)
  • If this MR fixes a bug that affects customers, the customer label has been applied.
• This MR has been approved by a maintainer (only one approval is required).
• Ensure the e2e:test-on-omnibus-ee job has succeeded, or if it has failed, investigate the failures. If you determine the failures are unrelated, you may proceed. If you need assistance investigating, request help in the #s_developer_experience Slack channel to confirm the failures are unrelated to the merge request.

Note to the merge request author and maintainer

If you have questions about the patch release process, please:

• Refer to the patch release runbook for engineers and maintainers for guidance.
• Ask questions on the #releases Slack channel (internal only).
• Once the backport has been merged, the commit changes will be automatically deployed to a release environment that can be used for manual validation. See after merging runbook for details.

References

• !261515 (merged)
• gitlab-org/editor-extensions/gitlab-lsp!4412 (merged)