build: drop pbs-buildcfg version hack

no longer needed, it inherits the workspace/proxmox-backup version now, there
is no risk of forgetting to update its version anymore.

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

Makefile

@@ -85,9 +85,6 @@ doc:
 # always re-create this dir
 .PHONY: build
 build:
-	@echo "Setting pkg-buildcfg version to: $(DEB_VERSION_UPSTREAM)"
-	sed -i -e 's/^version =.*$$/version = "$(DEB_VERSION_UPSTREAM)"/' \
-	  pbs-buildcfg/Cargo.toml
 	rm -rf build
 	mkdir build
 	cp -a debian \