…sue number in branch name (#30601) (#30707)

### Proposed Changes

This pull request introduces a new input parameter to the
`cicd_manual_publish-starter.yml` GitHub Actions workflow. The new input
parameter, `issue-number`, is used to create the PR branch in case of
the empty starter creation. Additionally, it adds a Slack notification
step to the workflow.

### Changes

1. **New Input Parameter**:
   - Introduce a new input parameter `issue-number`.
- This parameter is used to create the PR branch in case of the `Empty
Starter` creation.

2. **Message Composition**:
   - Construct a detailed message about the newly published starter.
- Include information such as starter type, artifact filename, artifact
URL, old assets included, and changelog.
   - Append the composed message to the GitHub Actions output.

3. **Slack Notification Step**:
   - Add a new step named "Slack Notification" to the workflow.
- Use the custom GitHub Action located at
`.github/actions/core-cicd/notification/notify-slack`.
   - Send a notification to the `log-starter` Slack channel.
   - Use the composed message as the payload for the Slack notification.
   - Retrieve the Slack bot token from GitHub Secrets.

### Motivation

The addition of the `issue-number` input parameter ensures that the PR
branch is correctly created in case of the `Empty Starter` creation. The
Slack notification step ensures that team members are promptly informed
about new starter publications, improving communication and awareness
within the team, and meeting with the Status Check validation on PR
branch naming conventions.

### Testing

- Verified that the `issue-number` input parameter is correctly handled
and used to create the PR branch.
- Verified that the message is correctly composed and appended to the
GitHub Actions output.
- Confirmed that the Slack notification is sent to the specified channel
with the correct payload.

### Additional Info
This PR resolves #30601 (Automatic pull request for empty starter fails
due to missing issue number in branch name).