Add a new workflow for Auto Comment on Labeled PR

[seokho-son]

This workflow is designed to automatically comment on pull requests based on the labels they are tagged with.
It aims to facilitate automated communication and status updates within the pull request process.

• Triggered on Labeling: The workflow is triggered whenever a pull request is labeled or unlabeled.
• Reads Config File: It reads an external YAML configuration file at .github/label_comments_config.yaml to determine which comments to add for specific sets of labels.
• Checks PR Labels: The workflow fetches the current labels attached to the pull request.
• Matches Labels: It compares these labels against sets of labels defined in the configuration file.
• Adds Comment: If a match is found, the workflow adds the corresponding comment to the pull request.