[Request] Replace GHCR_PR_TOKEN with GITHUB_TOKEN

[tthvo]

Describe the feature

Since the event is pull_request_target, the GITHUB_TOKEN is allowed to elevate its permission to write:packages. We can utilize this instead of the GHCR_PR_TOKEN PAT.

Tho, we will need to make sure to specify only necessary permissions.

Anything other information?

https://docs.github.com/en/actions/security-guides/automatic-token-authentication#permissions-for-the-github_token

[andrewazores]

Need to double check the permission elevation thing. It may work here since the event is pull_request_target as opposed to a comment, but: https://github.com/cryostatio/cryostat/pull/1631#issuecomment-1692439904

[tthvo]

Source: https://docs.github.com/en/actions/security-guides/automatic-token-authentication#permissions-for-the-github_token

If the default permissions for the GITHUB_TOKEN are restrictive, you may have to elevate the permissions to allow some actions and commands to run successfully.

Right! Permissions need to be explicitly elevated.

[tthvo]

https://github.com/cryostatio/cryostat/pull/1635#issuecomment-1694094452

[tthvo]

ping @aali309