rename verify-build-type target to verify-handbook-revision

Handbook/GNUmakefile

@@ -246,8 +246,8 @@ prepare-dest:
 prepare-src:
 	@echo "Preparing the handbook source dir $(SG_MDBOOK_SRC_DIR)..."
 
-.PHONY: verify-build-revision
-verify-build-revision:
+.PHONY: verify-handbook-revision
+verify-handbook-revision:
 ifeq ($(SG_HANDBOOK_REVISION), next)
 	@echo "Building an unstable handbook for the next release..."
 else # ($(SG_HANDBOOK_REVISION), next)
@@ -304,7 +304,7 @@ serve:
 build: info
 build: install-build-deps
 build: prepare
-build: verify-build-revision
+build: verify-handbook-revision
 build:
 
 .PHONY: deploy