Automate weekly pulumi/pulumi upgrade

[flostadler]

This sets up a cron job to bump pulumi/pulumi versions every week. The cron job updates the dependencies, rebuilds the provider and then opens a PR. The PR is set to auto merge.

Closes #1264

[iwahbe]

This looks like a good idea.

[iwahbe]

I'm having trouble understanding why this script isn't just

go get -u github.com/pulumi/pulumi/pkg/v3
go get -u github.com/pulumi/pulumi/sdk/v3
go mod tidy

[flostadler]

Yeah looking at it again you're right. I was a bit over-careful with logging exactly what's happening in the update steps, but that's just making the script harder to grasp.

The versioning bit I wanted to have in order to include that in the commit and PR info. It also ensure we have consistent versions across the modules PR. e.g. when a new pu/pu version is released midway through the workflow run; even if it's rather unlikely to happen

[t0yv0]

Err on the side of merging, can fixup or edit as needed I think. Thank you! One day perhaps a common way to do this in ci-mgmt but it doesn't have to be now.

[iwahbe]

Err on the side of merging, can fixup or edit as needed I think. Thank you! One day perhaps a common way to do this in ci-mgmt but it doesn't have to be now.

CC @danielrbradley who is working on unifying theses repos in ci-mgmt.