Feature request : Provide `alpine` based runner images

[grzesuav]

What would you like added?

Have small/thin alpine based images instead of fat ubuntu ones -

Image name: ghcr.io/actions/actions-runner:2.316.0                                                                                                                                        -
Total Image size: 916 MB

Why is this needed?

To provide faster spin up time of autoscaling runner group, lower network traffic etc

Additional context

Discussion link