Update artifacts/attributes.adoc

Author: themr0c

artifacts/attributes.adoc

@@ -13,7 +13,7 @@
 :product-version: 1.5
 :product-bundle-version: 1.5.0
 :product-chart-version: 1.5.0
-:product-backstage-version: 1.29.2
+:product-backstage-version: 1.31.3
 :rhdeveloper-name: Red Hat Developer
 :rhel: Red Hat Enterprise Linux
 :odf-name: OpenShift Data Foundation