Implement workspace internal dependency updater

[EduardGomezEscandell]

This workflow will keep internal dependencies updated.

UDENG-267

PS: Sorry for the force-pushing. I was testing commit signing 🤭

[EduardGomezEscandell]

@didrocks Was thinking about this. All our PR commits belong to the main branch because we use merge commits, so is this really doing anything useful?

It makes sense if you squash, since old commits become unreachable. But this is not the case here.
Maybe we could run this periodically (once a week?) to keep the imports up-to-date, but I'm not sure that would do anything either.

[didrocks]

I think the action should be more fine-grained, as if look at any of those common deps for last commit if there is any update in the go files. Then, only trigger the update hook.

However, thinking about it, the issue is about building the deb package, the rest is fine and good only be merged in the main branch. So, I’m wondering, could we trigger that on PR rather, check if there is any change in those common deps subdirectories, and in that case, run the action, and create a PR that is not automerged against your PR branch? WDYT?

[EduardGomezEscandell]

The way it works now:

• It only checks WSL-Pro-Service
• It looks at the dependency ref:

github.com/canonical/ubuntu-pro-for-windows/agentapi v0.0.0-20230906090052-60fb5d60ada4
                                            ^^^^^^^^                       ^^^^^^^^^^^^
                                            PATH                           COMMIT

• It checks if there is any diff in that submodule since that commit:

git diff ${COMMIT} -- ${PATH}

• If no diff, continue
• Otherwise: update the dependency

Then, only push the branch if anything changed.

This method should considerably reduce spam, although it'll still have some false positives, such as when editing non-code files in the dependencies. If this ever happens to be an issue, we can filter diffs by file extension; however I doubt this'll ever become an issue.

[didrocks]

Apart from the internal vs external scripts and env variables passing silently as argument, I agree with the current approach.

[didrocks]

… and using that opportunity to clean up some trailing spaces, I see you! :)