Drop header comment

Co-authored-by: Julian Rüth <[email protected]>

Author: soehms

.github/workflows/push_to_docker_hub.yml

@@ -1,20 +1,3 @@
-# This workflow replaces $SAGE_ROOT/.gitlab-ci.yml which has been
-# used formerly to make Docker images available on DockerHub.
-# The new workflow uses the same $SAGE_ROOT/docker/Dockerfile and
-# is based on docker/build-push-action@v4.
-#
-# A replacement has become neccessary because the GitLab runners
-# stopped to create new images since release 9.7.
-#
-# Concerning the images placed in the sagemath-dev repository you
-# should note the following difference to the releases build before
-# 9.8: They are no longer build on target sagemath-dev since this
-# causes a "No space left on device" error. Instead they are build
-# on target make-build, now. The main difference is the missing
-# documentation and that it enters in a bash shell.
-#
-# Sebastian Oehms, August 2023
-
 name: Build Docker images and push to DockerHub
 
 on: