feat!: add packages input that installs packages on the AWS instance as part of cloud-init

[yonch]

Installing packages in the pre-runner-script has been unreliable as it seems during boot there are other processes locking the package index. It appears the recommended way is to use the packages property of cloud-init.

This requires passing a cloud init YAML (starts with #cloud-config) as user data. Luckily this format is supported by AWS.

This PR:

• writes the pre-runner-script.sh and the main user-data script (runner-setup.sh) using cloud-init's write_files
• adds a cloud-init packages directive to install packages
• runs the main script using cloud-init's runcmd

This allows supporting multi-line pre-runner-script.sh. As a bonus, this greatly simplified strange escaping issues stemming from echo "${config.input.preRunnerScript}" > pre-runner-script.sh -- we tried to write a file inside the pre-runner-script which required multiple levels of nested escaping before this change, now this burden is greatly reduced.

Additionally, this PR causes the package, when installing the github runner, to install the latest version. Otherwise I've seen the runner updates itself on load, increasing the startup time. I thought this might be causing some issues while debugging the feature and added this according to github instructions. Since this works, I think we might as well merge this too and enjoy the reduced startup time.

[yonch]

There are cases where this change does not work. I'm closing for now, might reopen with updated code.

[yonch]

Hi @Preen, this is ready for review.

I ran this with workflows that auto-install the runner on:
ubuntu-22.04: https://github.com/yonch/collector/actions/runs/17324943448
ubuntu-24.04: https://github.com/yonch/collector/actions/runs/17325258198

and with a pre-runner script + packages:
https://github.com/yonch/linux/actions/runs/17325392651

[yonch]

fyi I re-tested after merging the main branch:

• with ubuntu-24.04 auto-install
• custom-runner-install + pre-runner script + packages

[Preen]

Hey @yonch Nice work!! Sorry for not getting back sooner. Im ready to test this week, however I can see there's some conflicts that needs to be resolved, are you able to look at them?

[yonch]

Hi @Preen, I rebased the patch, ready for review.

[Preen]

Tests looks good! Thank you @yonch !