Is your feature request related to a problem? Please describe.

Currently dapr/go-sdk depends on dapr/dapr just because of the exposed protos.
This creates unnecessary coupling of versions, in particular for projects that use both repositories.

Describe the solution you'd like

In my opinion, in an ideal world all generated protos in dapr/dapr would be internal/non-exported. Which is the same limitation other SDKs have to deal with, and also what makes them more robust in terms of dependencies.

There are many ways to accomplish compiling the protos in the go-sdk repo, but I believe probably the best one would be to introduce buf to the main dapr/dapr repo, which would make it easier to compile the protos here - with the benefit of lock files and so on. Potentially enabling other sdks in the process.

Describe alternatives you've considered

There are other ways for compiling the protos in the repo, like fetching them on ci, or using submodules. But probably buf is the more straight forward way.

Additional context