Automatic labeling of Github issues for GlideinWMS

[namrathaurs]

This pull request is the starting step towards achieving automatic labeling of issues for GlideinWMS when they are newly created. Before merging this pull request, a secret needs to be created under the repository settings for the issue labeler workflow. Otherwise, the third-party action invoked as part of the auto-labeling workflow will fail.

Details:

• The issue labeling workflow is based on the a third-party Github action found here that internally uses regular expressions.
• Color coding of the labels is recognized/used from the list of existing labels created within the repository.
• Requires a secret to be created under the repository settings for the workflow to succeed.
• Supports additional, optional attributes that need to be enabled/toggled for more advanced handling of issues and labeling them. For more information on how to achieve advanced handling, click the URL listed under the first bullet point.

Known limitation(s):

1. If multiple stakeholders are listed in the issue, only the first stakeholder listed will be assigned as a label and the rest of them will be ignored.
2. A message UnhandledPromiseRejectionWarning: HttpError: Label does not exist occurs when observed in the workflow run log. Looks like this might be because the third-party Github action tries to remove all other labels, listed in regexes-for-issue-labels.yaml after assigning the appropriate ones as decided by the regular expressions when applied.
   • a known issue with the third-party Github action

[namrathaurs]

The third-party Github action being used in this workflow uses GITHUB_TOKEN with read/write permissions set at the repository level. To determine if granting the RW permissions is safe, did a scan of the code that implements the underlying Github action as was suggested. No traces of security concerning code was found. It'd be great if another pair of eyes can give the code another look to be sure that anything critical or concerning has not been missed.

URL to the Github action: https://github.com/marketplace/actions/regex-issue-labeler