Dual-push images to Docker Hub and GHCR

Author: chadlwilson

.github/workflows/build.yml

@@ -37,7 +37,7 @@ jobs:
         uses: docker/login-action@v2
         with:
           registry: docker.io
-          username: ${{ DOCKER_HUB_ID }}
+          username: ${{ vars.DOCKER_HUB_ID }}
           password: ${{ secrets.DOCKER_HUB_TOKEN }}
 
       - name: ASDF setup