Remove outdated docs redirects

⚠ This MR should be merged after the MR in gitlab-docs: gitlab-docs!1898 (merged)

What does this MR do?

Remove outdated redirect files:

• doc/administration/auth/okta.md
• doc/administration/geo/replication/remove_geo_node.md
• doc/ci/chatops/README.md
• doc/ci/docker/README.md
• doc/ci/examples/test-and-deploy-python-application-to-heroku.md
• doc/ci/examples/test-and-deploy-ruby-application-to-heroku.md
• doc/ci/examples/test-clojure-application.md
• doc/ci/quick_start/README.md
• doc/ci/services/README.md
• doc/ci/ssh_keys/README.md
• doc/development/feature_flags/development.md
• doc/development/feature_flags/process.md
• doc/development/new_fe_guide/dependencies.md
• doc/development/usage_ping.md
• doc/downgrade_ee_to_ce/README.md
• doc/gitlab-basics/create-project.md
• doc/gitlab-basics/fork-project.md
• doc/gitlab-basics/README.md
• doc/install/README.md
• doc/integration/google_workspace_saml.md
• doc/intro/README.md
• doc/legal/README.md
• doc/operations/incident_management/alert_integrations.md
• doc/raketasks/README.md
• doc/security/cicd_environment_variables.md
• doc/university/README.md
• doc/university/training/gitlab_flow.md
• doc/university/training/topics/cherry_picking.md
• doc/university/training/topics/tags.md
• doc/update/README.md
• doc/user/admin_area/analytics/user_cohorts.md
• doc/user/project/integrations/jira_cloud_configuration.md
• doc/user/project/integrations/jira_server_configuration.md
• doc/user/project/merge_requests/work_in_progress_merge_requests.md
• doc/user/project/new_ci_build_permissions_model.md

Related issues

Part of regular TW maintenance: technical-writing#435 (closed)

Author's checklist (required)

• Follow the Documentation Guidelines and Style Guide.
• If you have Developer permissions or higher:
  • Ensure that the product tier badge is added to doc's h1.
  • Apply the documentation label, plus:
    • The corresponding DevOps stage and group labels, if applicable.
    • development guidelines when changing docs under doc/development/*, CONTRIBUTING.md, or README.md.
    • development guidelines and Documentation guidelines when changing docs under development/documentation/*.
    • development guidelines and Description templates (.gitlab/*) when creating/updating issue and MR description templates.
  • Request a review from the designated Technical Writer.

Do not add the feature, frontend, backend, ~"bug", or database labels if you are only updating documentation. These labels will cause the MR to be added to code verification QA issues.

When applicable:

• Update the permissions table.
• Link docs to and from the higher-level index page, plus other related docs where helpful.
• Add the product tier badge accordingly.
• Add GitLab's version history note(s).
• Add/update the feature flag section.

Review checklist

All reviewers can help ensure accuracy, clarity, completeness, and adherence to the Documentation Guidelines and Style Guide.

1. Primary Reviewer

• Review by a code reviewer or other selected colleague to confirm accuracy, clarity, and completeness. This can be skipped for minor fixes without substantive content changes.

2. Technical Writer

• Technical writer review. If not requested for this MR, must be scheduled post-merge. To request for this MR, assign the writer listed for the applicable DevOps stage.
  • Ensure docs metadata are present and up-to-date.
  • Ensure Technical Writing and documentation are added.
  • Add the corresponding docs:: scoped label.
  • If working on UI text, add the corresponding UI Text scoped label.
  • Add twdoing when starting work on the MR.
  • Add twfinished if Technical Writing team work on the MR is complete but it remains open.

For more information about labels, see Technical Writing workflows - Labels.

For suggestions that you are confident don't need to be reviewed, change them locally and push a commit directly to save others from unneeded reviews. For example:

• Clear typos, like this is a typpo.
• Minor issues, like single quotes instead of double quotes, Oxford commas, and periods.

For more information, see our documentation on Merging a merge request.

3. Maintainer

1. Review by assigned maintainer, who can always request/require the above reviews. Maintainer's review can occur before or after a technical writer review.
2. Ensure a release milestone is set.
3. If there has not been a technical writer review, create an issue for one using the Doc Review template.