Use standalone crddiff tool

Signed-off-by: Fatih Türken <[email protected]>

Makefile

@@ -85,6 +85,7 @@ UPTEST_LOCAL_CHANNEL = stable
 KUSTOMIZE_VERSION = v5.3.0
 YQ_VERSION = v4.40.5
 CROSSPLANE_VERSION = 1.14.6
+CRDDIFF_VERSION = v0.12.1
 
 export UP_VERSION := $(UP_VERSION)
 export UP_CHANNEL := $(UP_CHANNEL)
@@ -279,7 +280,7 @@ crddiff: $(UPTEST)
 			continue ; \
 		fi ; \
 		echo "Checking $${crd} for breaking API changes..." ; \
-		changes_detected=$$($(UPTEST) crddiff revision --enable-upjet-extensions <(git cat-file -p "$${GITHUB_BASE_REF}:$${crd}") "$${crd}" 2>&1) ; \
+		changes_detected=$$(go run github.com/upbound/uptest/cmd/crddiff@$(CRDDIFF_VERSION) revision --enable-upjet-extensions <(git cat-file -p "$${GITHUB_BASE_REF}:$${crd}") "$${crd}" 2>&1) ; \
 		if [[ $$? != 0 ]] ; then \
 			printf "\033[31m"; echo "Breaking change detected!"; printf "\033[0m" ; \
 			echo "$${changes_detected}" ; \