Xavier Thompson reports that when Theia is compiled inside Theia, Go
fails to install with the error showing that golang14's make.bash calls
go install to install cmd/go and other commands to the outer
go.work/bin instead of inside $GOROOT_FINAL set by the build recipe.
Similarly to !928 (merged) this
might be to the fact that internal go install prioritizes $GOBIN even
in the presence of set $GOROOT_FINAL.
-> Don't try to fix Go itself, and make the compilation more robust by
unsetting $GOBIN, so that even if that variable is set in the
environment where buildout runs, it does not affect the compilation
procedure.
