run: add --depot-auto-update feature

If enabled, this option triggers the automated management of depot
content according to the needs of a run script.

Fixes #3270

tool/builddir/build.conf/run

@@ -3,3 +3,6 @@
 ## Run-tool configuration
 ##
 
+# create depot archives and update recipe versions automatically
+#RUN_OPT += --depot-auto-update
+

tool/builddir/build.mk

@@ -323,6 +323,7 @@ run/%: $(call select_from_repositories,run/%.run) $(RUN_ENV)
 	                                     --repositories "$(REPOSITORIES)" \
 	                                     --cross-dev-prefix "$(CROSS_DEV_PREFIX)" \
 	                                     --qemu-args "$(QEMU_OPT)" \
+	                                     --make "$(MAKE)" \
 	                                     $(RUN_OPT) \
 	                                     --include $(RUN_SCRIPT)