[18-stable] Update Makefile for 18-stable

Author: ospk8s-branching-bot[bot]

Makefile

@@ -464,7 +464,7 @@ kuttl-test-cleanup:
 
 CRD_SCHEMA_CHECKER_VERSION ?= release-4.18
 
-BRANCH=main
+BRANCH=18-stable
 .PHONY: force-bump
 force-bump: ## Force bump operator and lib-common dependencies
 	for dep in $$(cat go.mod | grep openstack-k8s-operators | grep -vE -- 'indirect|watcher-operator|^replace' | awk '{print $$1}'); do \