message: chore(build) change the rootfs mount options when using make-push ot3
  The OT3 has a read-only rootfs so we need to set the mount options to read-write when using make push-ot3 then set the mount options back to read-only after our changes are pushed.
diff: @@ -36,9 +36,10 @@ define push-python-sdist
  $(if $(is-ot3), ,echo "This is an OT-2. Use 'make push' instead." && exit 1)
  scp $(if $(2),"-i $(2)") $(3) $(4) root@$(1):/var/$(notdir $(4))
  ssh $(if $(2),"-i $(2)") $(3) root@$(1) \
  -"function cleanup () { rm -f /var/$(notdir $(4)) ; rm -rf /var/$(notdir $(4))-unzip; } ; \
  +"function cleanup () { rm -f /var/$(notdir $(4)) ; rm -rf /var/$(notdir $(4))-unzip; mount -o remount,ro / ; } ;\
  mkdir -p /var/$(notdir $(4))-unzip ; \
  cd /var/$(notdir $(4))-unzip && tar xf ../$(notdir $(4)) ; \
  + mount -o remount,rw / ; \
  rm -rf $(5)/$(6) $(5)/$(6)*.egg-info ; \
  mv /var/$(notdir $(4))-unzip/$(basename $(basename $(notdir $(4))))/$(if $(7),$(7)/)$(6) $(5)/ ; \
  mv /var/$(notdir $(4))-unzip/$(basename $(basename $(notdir $(4))))/$(if $(7),$(7)/)$(6)*.$(if $(8),$(8),egg)-info $(5)/$(basename $(basename $(notdir $(4)))).$(if $(8),$(8),egg)-info ; \
  