Fix build errors in the dev-env

[ericcornelissen]

Summary

At some point building in the container started failing with the error:

error obtaining VCS status: exit status 128
        Use -buildvcs=false to disable VCS stamping.

this fixes that by adding the project directory inside the container as a folder trusted by git so that the Go compiler can get the VCS information.

An alternative would be to disable the VCS stamping, but it seems pretty useful to me to have this information available through go version -m ./ghasum for debugging purposes.