Feat/renovate custom chainguard matcher pt2 (#190260)

## Summary

Drops a comment for the current chaingaurd reference incase it is
implemented in a tech that requires endings other than `.ts`, and then
creates a PR grouping for the chainguard images.

renovate.json

@@ -20,6 +20,12 @@
       "matchDepPatterns": [".*"],
       "enabled": false
     },
+    {
+      "matchPackageNames": [
+        "docker.elastic.co/wolfi/chainguard-base"
+      ],
+      "enabled": true
+    },
     {
       "groupName": "GitHub actions",
       "matchManagers": ["github-actions"],

src/dev/build/tasks/os_packages/docker_generator/run.ts

@@ -42,6 +42,12 @@ export async function runDockerGenerator(
   let baseImageName = '';
   if (flags.baseImage === 'ubuntu') baseImageName = 'ubuntu:20.04';
   if (flags.baseImage === 'ubi') baseImageName = 'docker.elastic.co/ubi9/ubi-minimal:latest';
+  /**
+   * Renovate config contains a regex manager to automatically updates this Chainguard reference
+   *
+   * If this logic moves to another file or under another name, then the Renovate regex manager
+   * for automatic Chainguard updates will break.
+   */
   if (flags.baseImage === 'wolfi')
     baseImageName =
       'docker.elastic.co/wolfi/chainguard-base:latest@sha256:082266206be6e559baea1c8b2eeb4fb86ea1318a0cf99cbf0e612dd2c611e80b';