Deprecation - Upgrade Google COS image to the newest LTS version

data/deprecations/17-0-updating-cos-image-saas-runners.yml

+- title: "Upgrading the operating system version of GitLab SaaS runners on Linux"
+  removal_milestone: "17.0"
+  announcement_milestone: "16.9"
+  breaking_change: true
+  reporter: gabrielengel_gl
+  stage: Verify
+  issue_url: https://gitlab.com/gitlab-org/ci-cd/shared-runners/infrastructure/-/issues/60
+  manual_task: true
+  body: |  # (required) Don't change this line.
+    GitLab is upgrading the container-optimized operating system (COS) of the ephemeral VMs used to execute jobs for SaaS runners on Linux.
+    That COS upgrade includes a Docker Engine upgrade from Version 19.03.15 to Version 23.0.5, which introduces a known compatibility issue.
+
+    Docker-in-Docker prior to version 20.10 or Kaniko images older than v1.9.0, will be unable to detect the container runtime and fail.
+
+    For more information, see [Upgrading the operating system version of our SaaS runners on Linux](https://about.gitlab.com/blog/2023/10/04/updating-the-os-version-of-saas-runners-on-linux/).

doc/update/deprecations.md

@@ -1833,6 +1833,25 @@ You can still access unified approval rules with the API.
 
 <div class="deprecation breaking-change" data-milestone="17.0">
 
+### Upgrading the operating system version of GitLab SaaS runners on Linux
+
+<div class="deprecation-notes">
+- Announced in GitLab <span class="milestone">16.9</span>
+- Removal in GitLab <span class="milestone">17.0</span> ([breaking change](https://docs.gitlab.com/ee/update/terminology.html#breaking-change))
+- To discuss this change or learn more, see the [deprecation issue](https://gitlab.com/gitlab-org/ci-cd/shared-runners/infrastructure/-/issues/60).
+</div>
+
+GitLab is upgrading the container-optimized operating system (COS) of the ephemeral VMs used to execute jobs for SaaS runners on Linux.
+That COS upgrade includes a Docker Engine upgrade from Version 19.03.15 to Version 23.0.5, which introduces a known compatibility issue.
+
+Docker-in-Docker prior to version 20.10 or Kaniko images older than v1.9.0, will be unable to detect the container runtime and fail.
+
+For more information, see [Upgrading the operating system version of our SaaS runners on Linux](https://about.gitlab.com/blog/2023/10/04/updating-the-os-version-of-saas-runners-on-linux/).
+
+</div>
+
+<div class="deprecation breaking-change" data-milestone="17.0">
+
 ### Vulnerability confidence field
 
 <div class="deprecation-notes">