[BUG/Enhancement] Migrate to new dependabot workflow

[mcm1957]

Please adapt creator code to use new automerge action for dependabot.

Remove existing workflow file .github/workflows/dependabot-auto-merge.yml.

Add new workflowfile file .github/workflows/automerge-dependabot.yml based on https://github.com/iobroker-bot-orga/action-automerge-dependabot/blob/main/.github/workflows/automerge-dependabot.example.yml

existing config file .github/auto-merge.yml should be kept as it is.

Keep github token AUTO_MERGE_TOKEN. This token is no longer needed to merge but might be needed to trigger a recreate of the PR in case of problems. So keep this token.

Dependabot automerge setup is independent on adapter type, admin ui or js/ts or js/esm selection and should be identical in all possible variants.