EREGCSC-2883-B Remove Hello World stack

[addis-samtek]

This is a followup to EREGCSC-2883

Description

This PR cleans up the remove-experimental.yml action by removing a step that is no longer necessary.

This pull request changes...

• Deletes the remove step for the "hello world" stack because that stack does not exist anymore.
  • We added the deploy and remove steps in this PR: EREGCSC-2883 Deploy CDK via Github Actions (ready for review, ignore the red X) #1465
  • We deleted the deploy step in this PR a month ago, but didn't delete the remove step: EREGCSC-2860-B [Hotfix] Remove "hello world" stack deploy from deploy.yml #1481

Steps to manually verify this change...

• There should be no meaningful changes. Deployment scripts should work the same as before, because this is only removing an unnecessary step.

[github-actions]

✨ See the Django Site in action ✨

[PhilR8]

LGTM

[addis-samtek]

LGTM