feat: remove SUPPORT_TOKEN and use create-github-app-token

[lauramargar]

Pull request template

There was a security breach on https://oi.empathy.co/ which exposed one of our GitHub tokens with access to the organisations private repositories. The token is SUPPORT_TOKEN, so now we have to remove this token from our workflows and replace it with create-github-app-token action that generates tokens under demand.

Documentation: https://developer.empathy.co/ci-cd/github-actions.html#interact-with-github-private-resources-from-a-github-workflow

Example: https://github.com/empathyco/platform-motive-helm-charts/blob/a44f5bf359ca59c8fbe5bdafc678bde4959a4491/.github/workflows/version-updater.yaml#L43-L61

Motivation and context

• Dependencies. If any, specify:
• Open issue. If applicable, link:

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that causes existing functionality to not work as expected)
• Change requires a documentation update

What is the destination branch of this PR?

• Main
• Other. Specify:

How has this been tested?

Tests performed according to testing guidelines:

Checklist:

• My code follows the style guidelines of this project.
• I have performed a self-review on my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.