Remove Go Get Update workflow

[sophiewigmore]

Summary

Remove the Go Get Update workflow from implementation buildpacks.
Check out this thread in Paketo Slack for conversations around the removal of this workflow.

As of dependabot/dependabot-core#6361, I think that Dependabot can handle transitive dependencies in the go.mod, which wasn't the case when the workflow here was introduced. I think it requires some extra dependabot config

Use Cases

Checklist

• I have viewed, signed, and submitted the Contributor License Agreement.
• I have linked issue(s) that this PR should close using keywords or the Github UI (See docs)
• I have added an integration test, if necessary.
• I have reviewed the styleguide for guidance on my code quality.
• I'm happy with the commit history on this PR (I have rebased/squashed as needed).

[robdimsdale]

It was a little tricky to find example configuration, but I think it looks like the following:

version: 2
updates:
  - package-ecosystem: gomod
    directory: /
    schedule:
      interval: daily
    allow:
      # Allow both direct and indirect updates for all packages
      - dependency-type: "all"

In Dependabot terminology, indirect dependencies are what we are referring to as transitive dependencies.