build: remove S3_BUCKET var so binaries are not published

[jbw976]

Description of your changes

The storage of outputs to s3 is not needed by provider repos. Their important artifact is the container image which will still be published to dockerhub.

This is a similar issue that previously affected the other providers in https://github.com/crossplane/crossplane/issues/1320

Checklist

I have:

• [x] Run make reviewable to ensure this PR is ready for review.
• [x] Ensured this PR contains a neat, self documenting set of commits.
• [x] Updated any relevant documentation, examples, or release notes.
• [x] Updated the dependencies in app.yaml to include any new role permissions.
• [x] Updated the package resources documentation to include any new managed resources or classes.

[hasheddan]

@jbw976 looks like this is having trouble building. I am AFK but it looks like this is using a newer build commit hash than other providers, so not sure if that is related. I'll take a closer look later on today if you don't get to it first :)

[jbw976]

yes @hasheddan i think this would require a newer version of the build submodule after https://github.com/upbound/build/pull/95. This repo is currently using https://github.com/upbound/build/tree/317820ea3e6f9362e62654f31a0bcdb3947de3e3, which is older than that commit.

I am of the belief that you should continue enjoying your time off, and not mess with this 🤪

[jbw976]

I've pushed a commit to this PR to update the build submodule to https://github.com/upbound/build/tree/6224f247a26b91305dc185fdc99cb35579bad79c, the exact same version that provider-{aws, azure, gcp} are all using :)