Use DATA_built to add the main SQL file

Makefile

@@ -7,6 +7,7 @@ DISTVERSION  = $(shell grep -m 1 '[[:space:]]\{3\}"version":' META.json | \
 
 MODULEDIR    = $(EXTENSION)
 DATA         = $(wildcard sql/*.sql)
+DATA_built   = sql/$(EXTENSION)--$(EXTVERSION).sql
 DOCS         = $(wildcard doc/*.mmd)
 TESTS        = $(wildcard test/sql/*.sql)
 REGRESS      = $(patsubst test/sql/%.sql,%,$(TESTS))
@@ -23,8 +24,6 @@ endif
 PGXS := $(shell $(PG_CONFIG) --pgxs)
 include $(PGXS)
 
-all: sql/$(EXTENSION)--$(EXTVERSION).sql
-
 sql/$(EXTENSION)--$(EXTVERSION).sql: sql/$(EXTENSION).sql
 	cp $< $@