Automatically add issues in protocol and TC repos to their GitHub projects

[magnusbaeck]

Description

The TC and protocol maintainers use GitHub projects to track incoming and ongoing tasks in projects but currently rely on manually adding issues to the projects. Let's automate this with actions/add-to-project.

Specifically,

• new issues in TC-owned repositories (at least community, eiffel-sepia, eiffel-repository-template) should be added to the Technical Committee Tasks project, and
• new issues in the protocol repository should be added to the Eiffel Protocol project.

Motivation

See Benefits.

Exemplification

N/A

Benefits

• Decreased risk of forgetting issues.
• Easier to prioritize them.

Possible Drawbacks

None.

[magnusbaeck]

It turns out that GitHub's project feature has a built-in auto-add workflow that you can enable via point-and-click, but unless you have GitHub Enterprise you can only have one such workflow per project and only one repository per workflow. I've configured the Eiffel Protocol project to add issues from the protocol repo but for the TC project we'll have to add a workflow that uses actions/add-to-project.

[magnusbaeck]

Also, the default GITHUB_TOKEN token is only repository-scoped, and getting a token that allows you to add issues to a project requires either a PAT or a GitHub App. Creating and adding a PAT for this doesn't feel quite right.