Add @radius-project/on-call ownership for dependabot managed files (#1569)

* Add @radius-project/on-call ownership for dependabot files

Assign @radius-project/on-call group as owners for dependency files
that are automatically updated by dependabot (package.json and
package-lock.json). This ensures proper review and approval of
dependency updates by the on-call team.

Signed-off-by: Karishma Chawla <[email protected]>

* Include maintainers and approvers in dependabot file ownership

Add @radius-project/maintainers-docs and @radius-project/approvers-docs
to dependabot managed files to preserve existing access rights alongside
the on-call team.

Signed-off-by: Karishma Chawla <[email protected]>

---------

Signed-off-by: Karishma Chawla <[email protected]>

Author: kachawla

.github/CODEOWNERS

@@ -1,2 +1,6 @@
 # These owners are the maintainers and approvers of this repo
-*       @radius-project/maintainers-docs @radius-project/approvers-docs
+*       @radius-project/maintainers-docs @radius-project/approvers-docs
+
+# Dependabot managed files
+docs/package.json        @radius-project/on-call @radius-project/maintainers-docs @radius-project/approvers-docs
+docs/package-lock.json   @radius-project/on-call @radius-project/maintainers-docs @radius-project/approvers-docs