Build: Allow extending of LDFLAGS in build.go (#18954)
Build: Allow extending of LDFLAGS in build.go (#18954)

Allow extending LDFALGS by setting LDFLAGS to be able to pass
-zrelro,-znow for Arch Linux packaging
to get full relro.
grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana,grafana/grafana