build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/sigs.k8s.io/json/Makefile

@@ -0,0 +1,35 @@
+.PHONY: default build test benchmark fmt vet
+
+default: build
+
+build:
+	go build ./...
+
+test:
+	go test sigs.k8s.io/json/...
+
+benchmark:
+	go test sigs.k8s.io/json -bench . -benchmem
+
+fmt:
+	go mod tidy
+	gofmt -s -w *.go
+
+vet:
+	go vet sigs.k8s.io/json
+
+	@echo "checking for external dependencies"
+	@deps=$$(go list -f '{{ if not (or .Standard .Module.Main) }}{{.ImportPath}}{{ end }}' -deps sigs.k8s.io/json/... || true); \
+	if [ -n "$${deps}" ]; then \
+		echo "only stdlib dependencies allowed, found:"; \
+		echo "$${deps}"; \
+		exit 1; \
+	fi
+
+	@echo "checking for unsafe use"
+	@unsafe=$$(go list -f '{{.ImportPath}} depends on {{.Imports}}' sigs.k8s.io/json/... | grep unsafe || true); \
+	if [ -n "$${unsafe}" ]; then \
+		echo "no dependencies on unsafe allowed, found:"; \
+		echo "$${unsafe}"; \
+		exit 1; \
+	fi