chore: remove unnecessary workflows

[takayuki5168]

Description

Removed unnecessary workflows which are not used now

• .github/workflows/create-awf-latest.yml
  • Already disabled. I created this before, but instead, sync-awf-latest.yml is used.
• Sync for reference design
  • Already disabled
  • .github/workflows/sync-awf-latest-s1.yaml
  • .github/workflows/sync-awf-latest-x1.yaml
  • .github/workflows/sync-awf-latest-x2.yaml
  • .github/workflows/sync-awf-latest-xx1.yaml

Tests performed

No need

Effects on system behavior

Nothing

Pre-review checklist for the PR author

The PR author must check the checkboxes below when creating the PR.

• I've confirmed the contribution guidelines.
• The PR follows the pull request guidelines.

In-review checklist for the PR reviewers

The PR reviewers must check the checkboxes below before approval.

• The PR follows the pull request guidelines.

Post-review checklist for the PR author

The PR author must check the checkboxes below before merging.

• There are no open discussions or they are tracked via tickets.

After all checkboxes are checked, anyone who has write access can merge the PR.

[tkimura4]

.github/workflows/sync-tier4-upstream.yaml
Already disabled and not used https://github.com/tier4/autoware_launch/actions/workflows/sync-tier4-upstream.yaml

I think there is no need to delete this workflow, as it is intended for use in the repository created by forking autoware_launch.

[takayuki5168]

@tkimura4
Thank you for the comment. I added it in the top of the yaml file.

[tkimura4]

LGTM