[protobuf] make proton binaries build optional

[redbaron]

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

When cross compiling, it always build host version of protobuf to make protoc binaries available.

Not all codebases require them, if generated protobuf classes are committed to the source there is no use for protoc. Building protobuf for the host triplet makes builds unnecessary longer for these cases.

Proposed solution

Add a feature to make protoc binaries build optional.

Describe alternatives you've considered

No response

Additional context

No response