Fix macOS build after doc/help.json change

After #78126 merge, there is no data/doc folder anymore, as help.json
become "a thing" so to speak.

This causes errors on macOS build, as part of dmg assembly we do need to
copy all folders, and mv (at least on macOS) is strict in relation to
the missing path.

The fix is essentially remove all mentions to old data/doc from
Makefile..

Makefile

@@ -1123,7 +1123,7 @@ $(TEST_MO): data/mods/TEST_DATA/lang/po/ru.po
 
 MO_DEPS := \
   $(wildcard lang/*.sh lang/*.py src/*.cpp src/*.h) \
-  $(shell find data/raw data/json data/mods data/core data/help -type f -name '*.json')
+  $(shell find data/raw data/json data/mods data/core -type f -name '*.json')
 
 lang/mo_built.stamp: $(MO_DEPS)
 	$(MAKE) -C lang
@@ -1175,7 +1175,6 @@ install: version $(TARGET)
 	cp -R --no-preserve=ownership data/motd $(DATA_PREFIX)
 	cp -R --no-preserve=ownership data/credits $(DATA_PREFIX)
 	cp -R --no-preserve=ownership data/title $(DATA_PREFIX)
-	cp -R --no-preserve=ownership data/help $(DATA_PREFIX)
 ifeq ($(TILES), 1)
 	cp -R --no-preserve=ownership gfx $(DATA_PREFIX)
 	install -Dm755 -t $(SHARE_DIR)/applications/ data/xdg/org.cataclysmdda.CataclysmDDA.desktop
@@ -1210,7 +1209,6 @@ install: version $(TARGET)
 	cp -R --no-preserve=ownership data/motd $(DATA_PREFIX)
 	cp -R --no-preserve=ownership data/credits $(DATA_PREFIX)
 	cp -R --no-preserve=ownership data/title $(DATA_PREFIX)
-	cp -R --no-preserve=ownership data/help $(DATA_PREFIX)
 ifeq ($(TILES), 1)
 	cp -R --no-preserve=ownership gfx $(DATA_PREFIX)
 	install -Dm755 -t $(SHARE_DIR)/applications/ data/xdg/org.cataclysmdda.CataclysmDDA.desktop
@@ -1269,7 +1267,6 @@ endif
 	cp -R data/motd $(APPDATADIR)
 	cp -R data/credits $(APPDATADIR)
 	cp -R data/title $(APPDATADIR)
-	cp -R data/help $(APPDATADIR)
 ifdef LANGUAGES
 	$(MAKE) -C lang
 	mkdir -p $(APPRESOURCESDIR)/lang/mo/