chore: Bump OPA to 1.16.2 (#970)

Author: sbernauer

tests/test-definition.yaml

@@ -28,7 +28,7 @@ dimensions:
       - 3.9.4
   - name: opa-latest
     values:
-      - 1.12.3
+      - 1.16.2
   - name: upgrade_old
     values:
       - 3.9.1