Bumps the go-plugin package to pick up a bugfix that broke our project
on Windows. Our project uses the Vault SDK and we'd like to bump to the
latest, but can't until the Windows bugfix is picked up.

I had some issues with the go tooling, it wasn't quite happy with the
current state of go.mod. Forcing an upgrade of go-plugin to the same
version that currently appears in go.mod resulted in many other
dependency changes, so I resorted to editing manually ... what am I
doing wrong?

Thanks in advance for your help here