Update Docker image tag to include docker.io prefix

Author: DarshanScripts

.github/workflows/docker-pipeline.yml

@@ -28,6 +28,6 @@ jobs:
           context: .
           file: ./Dockerfile
           push: true
-          tags: darshanscripts/domain-modelling-copilot:latest
+          tags: docker.io/darshanscripts/domain-modelling-copilot:latest
           cache-from: type=registry,ref=darshanscripts/domain-modelling-copilot:latest
           cache-to: type=inline