This reverts commit 1c26a4abb0c9e095b3f6ec9944c4b15f6f1cd064, reversing
changes made to 186824a568583d8f6f2a50501d940ed71608fa0b.
The changes broke plugin loading when using subcommands so these
changes will be reverted until the underlying issue can be
investigated and resolved.
These changes address the following warning showing up on `go get`
operations:
go: module github.com/golang/protobuf is deprecated: Use the
"google.golang.org/protobuf" module instead.
All changes are made using the recommendations in the per-function
deprecation notices from the docs at
https://pkg.go.dev/github.com/golang/protobuf/ptypes