Don't use a different image to trigger the buildbox-e2e rebuild
Description
The recent e2e MR had an action that only triggers on the master branch which fails. The reason is that it specifies a new image to use ubuntu:bionic
which doesn't have the necessary python modules to run the before_script
block. The current image used already has curl, so just use that.
Changes proposed in this merge request:
- Fix CI by not using a new image in
trigger-buildbox-e2e-rebuild