use release-16 for envtest to be compatible with golang 1.19

kubernetes-sigs/controller-runtime#2720
Signed-off-by: Christian Groschupp <[email protected]>

Author: cgroschupp

opensearch-operator/Makefile

@@ -139,4 +139,4 @@ $(MOCKERY): $(LOCALBIN)
 .PHONY: envtest
 envtest: $(ENVTEST) ## Download envtest-setup locally if necessary.
 $(ENVTEST): $(LOCALBIN)
-	test -s $(LOCALBIN)/setup-envtest || GOBIN=$(LOCALBIN) go install sigs.k8s.io/controller-runtime/tools/setup-envtest@latest
+	test -s $(LOCALBIN)/setup-envtest || GOBIN=$(LOCALBIN) go install sigs.k8s.io/controller-runtime/tools/setup-envtest@release-0.16