Update base image stability tag to 2.15.4

Author: wodbot

.github/workflows/workflow.yml

@@ -9,7 +9,7 @@ on:
     - '*'
 
 env:
-  BASE_IMAGE_STABILITY_TAG: 2.15.3
+  BASE_IMAGE_STABILITY_TAG: 2.15.4
   DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
   DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}