remove publish to Dockerhub

Author: andrewelamb

.github/workflows/CI.yml

@@ -138,10 +138,6 @@ jobs:
         with: { name: python-distribution-files, path: dist/ }
       - uses: docker/setup-qemu-action@v2
       - uses: docker/setup-buildx-action@v2
-      - uses: docker/login-action@v2
-        with:
-          username: ${{ secrets.DOCKER_USERNAME }}
-          password: ${{ secrets.DOCKER_PASSWORD }}
       - uses: docker/login-action@v2
         with:
           registry: ghcr.io