CODEOWNERS update for Dependabot and GitHub Actions dependencies (#44)

Signed-off-by: Brooke Hamilton <45323234+brooke-hamilton@users.noreply.github.com>

Author: brooke-hamilton

.github/CODEOWNERS

@@ -1,6 +1,13 @@
 # These owners are the maintainers and approvers of this repo
 *       @radius-project/maintainers-docs @radius-project/approvers-docs
 
-# Allows on-call members to respond to changes in .github files
+# Ownership for dependency-related files. Allow the on-call team to approve
+# dependency version updates (e.g., from Dependabot PRs)
+
+# GitHub Actions workflow files (updated by Dependabot github-actions ecosystem)
+.github/workflows/*.yaml  @radius-project/on-call @radius-project/maintainers-docs @radius-project/approvers-docs
+.github/workflows/*.yml   @radius-project/on-call @radius-project/maintainers-docs @radius-project/approvers-docs
+
+# GitHub config files (includes dependabot.yml, etc.)
 .github/*.yaml    @radius-project/on-call @radius-project/maintainers-docs @radius-project/approvers-docs
 .github/*.yml     @radius-project/on-call @radius-project/maintainers-docs @radius-project/approvers-docs