Unable to verify the tool version when installed with go install

[roarc0]

🐛 Bug Report

Installing the tool with go install installs a binary that is not capable of reporting the version.

To Reproduce

1. go install github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-grpc-gateway@v2.15.2
2. protoc-gen-grpc-gateway --version

Expected behavior

Version v2.15.2, commit xxxx, built at xxxx

Actual Behavior

Version dev, commit unknown, built at unknown

[johanbrandhorst]

I don't know if it's possible to make this work the way we do it today, since the version is passed into the binary at build time. We'd have to store a constant in the Go files instead.