makefile - pin setup-envtest to a version instead of latest

CI reports incompatible go version:

GOBIN=/home/zuul-worker/src/softwarefactory-project.io/software-factory/sf-operator/bin go install sigs.k8s.io/controller-runtime/tools/setup-envtest@latest
go: downloading sigs.k8s.io/controller-runtime/tools/setup-envtest v0.0.0-20240322105421-affb96708000
go: downloading sigs.k8s.io/controller-runtime v0.17.2
go: sigs.k8s.io/controller-runtime/tools/setup-envtest@latest: sigs.k8s.io/controller-runtime/tools/setup-envtest@v0.0.0-20240322105421-affb96708000 requires go >= 1.22.0 (running go 1.21.7; GOTOOLCHAIN=local)

https: //pkg.go.dev/sigs.k8s.io/controller-runtime/tools/setup-envtest?tab=versions
Change-Id: I023a613d7a50e28a4c515eeb754dcb714c4c2586

Makefile

@@ -169,6 +169,7 @@ CONTROLLER_TOOLS_VERSION ?= v0.13.0
 OPERATOR_SDK_VERSION ?= 1.32.0
 STATICCHECK_VERSION ?= 2023.1.6
 MKDOCS_VERSION ?= 1.5.3
+SETUP_ENVTEST_VERSION ?= v0.0.0-20240320141353-395cfc7486e6
 
 .PHONY: mkdocs
 mkdocs: $(MKDOCS) ## Install material for mkdocs locally if necessary
@@ -189,7 +190,7 @@ $(CONTROLLER_GEN): $(LOCALBIN)
 .PHONY: envtest
 envtest: $(ENVTEST) ## Download envtest-setup locally if necessary.
 $(ENVTEST): $(LOCALBIN)
-	GOBIN=$(LOCALBIN) go install sigs.k8s.io/controller-runtime/tools/setup-envtest@latest
+	GOBIN=$(LOCALBIN) go install sigs.k8s.io/controller-runtime/tools/setup-envtest@$(SETUP_ENVTEST_VERSION)
 
 .PHONY: operator-sdk
 operator-sdk: $(OPERATOR_SDK)