Improve Compatibility with Fork Based Contributions

[mmcky]

A key issue with fork based contributions is that they don't execute due to the need to use GitHub secrets in the execution phase and GitHub disables that access.

• research improvements to this workflow to see if others have solved this issue.
• minimise the number of repos that use EC2 to execute

It is particularly problematic on EC2 organised workflows as we can't ask GitHub to enable the workflow run. Workflows that use GitHub actions directly does enable us to allow it to run (based on permission requests)

[mmcky]

https://docs.github.com/en/actions/managing-workflow-runs/approving-workflow-runs-from-public-forks