fix: Release tag checks for make pre-release

Author: nicfit

Makefile

@@ -132,7 +132,7 @@ pre-release: lint test changelog requirements
 	@echo "RELEASE_TAG: $(RELEASE_TAG)"
 	@echo "RELEASE_NAME: $(RELEASE_NAME)"
 	check-manifest
-	@if git tag -l | grep -E '^$(shell echo $${RELEASE_TAG} | sed 's|\.|.|g')$$' > /dev/null; then \
+	@if git tag -l | grep -E '^$(shell echo ${RELEASE_TAG} | sed 's|\.|.|g')$$' > /dev/null; then \
         echo "Version tag '${RELEASE_TAG}' already exists!"; \
         false; \
     fi

cookiecutter/{{cookiecutter.project_name}}/Makefile

@@ -143,7 +143,7 @@ pre-release: lint test changelog requirements
 	@echo "RELEASE_TAG: $(RELEASE_TAG)"
 	@echo "RELEASE_NAME: $(RELEASE_NAME)"
 	check-manifest
-	@if git tag -l | grep -E '^$(shell echo $${RELEASE_TAG} | sed 's|\.|.|g')$$' > /dev/null; then \
+	@if git tag -l | grep -E '^$(shell echo ${RELEASE_TAG} | sed 's|\.|.|g')$$' > /dev/null; then \
         echo "Version tag '${RELEASE_TAG}' already exists!"; \
         false; \
     fi