Add authentication to ghcr.

Author: paulus

.github/workflows/build.yml

@@ -182,6 +182,12 @@ jobs:
         with:
           repository: 'OSGP/gxf-gitops'
           ref: 'feature/FDP-3056-smhe-cucumber-containers'
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
       - name: Setup k3d cluster
         run: bash setup.sh
       - name: Create gxf platform