Find alternate DCO commit check

[foundrytom]

What

Find a replacement for the current DCO CI check process

Timeboxed to 1 day intially

Why

Node.js 12 actions are deprecated. For more information see: https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/. Please update the following actions to use Node.js 16: tim-actions/get-pr-commits, tim-actions/dco

This hasn't been update yet, and has known issues with longer PRs

Notes

• There may be something built into GitHub now?
• We've previously hit issues with large numbers of commits and variable passing so a self-contained action would be preferred.

[JeanChristopheMorinPerso]

https://github.com/apps/dco is really nice and works quite nicely. It's what's used in the ASWF organization. GitHub are also working on a native DCO check if I'm not mistaken but I haven't heard any news about that recently.

[feltech]

I added the https://github.com/apps/dco app to my personal account and pushed a dummy PR: feltech#10 - looks good to me!

[feltech]

I can't add the DCO app to the OpenAssetIO org myself - I've "requested" it. Presumably @foundrytom will have to approve.

[feltech]

Added #731 to remove the current action once the app is approved.

The only other repo where we do DCO checks is otio-openassetio.

So added OpenAssetIO/otio-openassetio#11 to update that.

The app should apply to all repos in the org, which is cool.

Closing this now, since it was just an investigation and this looks like a great solution. Thanks @JeanChristopheMorinPerso !