remove dependency on go-genproto

### What version of rules_go are you using?

v0.26.0

### What version of gazelle are you using?

v0.23.0

### What version of Bazel are you using?

4.0.0

### Does this issue reproduce with the latest releases of all the above?

Yes

### What operating system and processor architecture are you using?

Linux / MacOS, AMD64.

### What did you do?

Used rules_go with [cloud.google.com/go](https://github.com/googleapis/google-cloud-go).

### What did you expect to see?

A build that compiled.

### What did you see instead?

The build failed due to rules_go declaring an older version of [go-genproto](https://github.com/googleapis/go-genproto). It is possible to get everything working by using the override instructions but that is not super intuitive. Unless there is a need for the genproto to be bundled I suggest removing the dependency on it so users of rules_go can more easily use the latest version of cloud.google.com/go without the need for overriding dependencies.

Start by examining rules_go's dependency declarations and the override instructions referenced in the issue, then reproduce the cloud.google.com/go build with the stated rules_go, Gazelle, and Bazel versions. Done means the build compiles without requiring users to override the go-genproto dependency.

Written by the indexing model from the issue text.