Use Dependabot to update Go modules

[cbandy]

The golang.org/x modules are a frequent source of vulnerabilities. Let's update them regularly to keep security fixes small.

Checklist:

• Have you added an explanation of what your changes do and why you'd like them to be included?
• Have you updated or added documentation for the change, as applicable?
• Have you tested your changes on all related environments with successful results, as applicable?
  • Have you added automated tests?

Type of Changes:

• Testing enhancement

What is the new behavior (if this is a feature change)?

We'll get the following pull requests immediately, and then similar ones weekly. Any that we don't merge are updated and rebased weekly.

• Bump the opentelemetry group with 6 updates cbandy/postgres-operator#22
• Bump the go-dependencies group with 8 updates cbandy/postgres-operator#23
• Bump the kubernetes group across 1 directory with 7 updates cbandy/postgres-operator#24

Other Information:

Dependabot validated the config file in my fork: https://github.com/cbandy/postgres-operator/runs/43355908899