ci: move from dependabot reviewers to CODEOWNERS

Author: oakrizan

.github/CODEOWNERS

@@ -1,3 +1,3 @@
 * @elastic/elastic-agent-control-plane
-/.github/actions @elastic/observablt-ci
-/.github/workflows @elastic/observablt-ci
+/.github/actions @elastic/observablt-ci @elastic/observablt-ci-contractors
+/.github/workflows @elastic/observablt-ci @elastic/observablt-ci-contractors

.github/dependabot.yml

@@ -9,9 +9,6 @@ updates:
       interval: "weekly"
       day: "sunday"
       time: "22:00"
-    reviewers:
-      - "elastic/observablt-ci"
-      - "elastic/observablt-ci-contractors"
     groups:
       github-actions:
         patterns: