rules.mk: add DEPRECATION NOTICE for AUTORELEASE

Add DEPRECATION NOTICE for AUTORELEASE to signal that any usage of this
should be dropped and fixed.

The macro is still defined for legacy reason but we at least dropped any
usage of it in both main and feeds.

Link: https://github.com/openwrt/openwrt/pull/20586
Signed-off-by: Christian Marangi <[email protected]>

rules.mk

@@ -515,6 +515,7 @@ define commitcount
 $(shell \
   if git log -1 --no-show-signature >/dev/null 2>/dev/null; then \
     if [ -n "$(1)" ]; then \
+      $(call ERROR_MESSAGE,DEPRECATION NOTICE: The use of AUTORELEASE has been deprecated. Fix your Makefile.); \
       last_bump="$$(git log --no-show-signature --pretty=format:'%h %s' . | \
         grep -m 1 -e ': [uU]pdate to ' -e ': [bB]ump to ' | \
         cut -f 1 -d ' ')"; \