ci: update df image to use latest hpx

also removes some old copies in dockerfile that were meant to reduce
image size. However, as many entities need to be copied now, we might
need to have a better approach for this (using make install maybe), and
copy everything that is necessary into the right place.

.github/workflows/continuous-integration.yml

@@ -807,8 +807,8 @@ jobs:
       - name: Build Tag and Publish
         if: ${{ steps.login.conclusion != 'skipped' }}
         run: |
-          docker build -t $IMAGE:libc_2_28 -f builders/Dockerfile.hpx-env .
-          docker push $IMAGE:libc_2_28
+          docker build -t $IMAGE -f builders/Dockerfile.hpx-env .
+          docker push $IMAGE:latest
 
       - name: Is Image Built
         id: is-built