Backport GITLAB_ZOEKT_INDEXER v1.8.2

What does this MR do and why?

Bumps GITLAB_ZOEKT_VERSION from 1.8.0 to 1.8.2 on 18-9-stable-ee.

v1.8.2 is a backport of gitlab-org/gitlab-zoekt-indexer!852 which fixes a bug where the Zoekt indexer incorrectly performs an incremental index after a force push, resulting in stale or missing search results for self-managed customers on GitLab 18.9.

It also includes an additional schema_version bump to keep all backports at the same schema_version

• Original issue: #593947 (closed)
• Original MR: gitlab-zoekt-indexer!852 (merged)

This backport (which fixes the reindex when schema_version is bumped) is also merged in 18.9

Backport- Use force_index_repo task type for Zo... (!231461 - merged)

Backport chain for 18.9 (SM)

1. ✅ gitlab-zoekt-indexer — cherry-picked fix onto v1.8.0, tagged v1.8.2
2. ✅ gitlab-org/build/CNG — gitlab-org/build/CNG!2896 (merged), builds cng/gitlab-zoekt:v1.8.2 on 18-9-stable
3. ⭐ gitlab-org/gitlab — this MR on 18-9-stable-ee bumping GITLAB_ZOEKT_VERSION to 1.8.2
4. ⏳ cloud-native/charts/gitlab-zoekt — MR on main bumping chart to 3.8.4 with image v1.8.2
5. ⏳ gitlab-org/charts/gitlab — MR on 9-9-stable bumping gitlab-zoekt to 3.8.4

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, reach out to a Software Engineer in Test in #s_developer_experience.

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.