Makefile.include: rename Makefile.ci target to create-Makefile.ci

If we

    -include Makefile.ci

and `Makefile.ci` does not exist, but we provide `make` with a way
on how to do so, it will try to create `Makefile.ci`.

This is not what we want, but I don't know how to disable this automagic.
So rename the target to `create-Makefile.ci` to avoid the conflict.

Makefile.include

@@ -222,7 +222,7 @@ GLOBAL_GOALS += buildtest \
                 info-boards-features-missing \
                 info-boards-supported \
                 info-buildsizes info-buildsizes-diff \
-                Makefile.ci \
+                create-Makefile.ci \
                 #
 
 ifneq (, $(filter $(GLOBAL_GOALS), $(MAKECMDGOALS)))

makefiles/info-global.inc.mk

@@ -143,7 +143,7 @@ info-boards-features-blacklisted:
 info-boards-features-conflicting:
 	@for f in $(BOARDS_FEATURES_CONFLICTING); do echo $${f}; done | column -t
 
-Makefile.ci:
+create-Makefile.ci:
 	@$(RIOTTOOLS)/insufficient_memory/create_makefile.ci.sh --no-docker
 
 # Reset BOARDSDIR so unchanged for makefiles included after, for now only

makefiles/info.inc.mk

@@ -5,7 +5,7 @@
         info-debug-variable-% info-toolchains-supported \
         check-toolchain-supported \
         info-programmers-supported \
-        Makefile.ci \
+        create-Makefile.ci \
         #
 
 info-objsize: