Get Makefile dependency versions from go.mod

Makefile

@@ -94,6 +94,10 @@ ifneq ($(strip $(GINKGO_SKIP)),)
 _SKIP_ARGS := $(foreach arg,$(strip $(GINKGO_SKIP)),-skip="$(arg)")
 endif
 
+# Helper function to get dependency versions from go.mod instead of having to
+# hardcode them in the Makefile.
+get_go_version = $(shell go list -m $1 | awk '{print $$2}')
+
 #
 # Binaries.
 #
@@ -125,8 +129,8 @@ CONVERSION_GEN_BIN := conversion-gen
 CONVERSION_GEN := $(abspath $(TOOLS_BIN_DIR)/$(CONVERSION_GEN_BIN))
 CONVERSION_GEN_PKG := k8s.io/code-generator/cmd/conversion-gen
 
-ENVSUBST_VER := v2.0.0-20210730161058-179042472c46
 ENVSUBST_BIN := envsubst
+ENVSUBST_VER := $(call get_go_version,$(github.com/drone/envsubst/v2))
 ENVSUBST := $(abspath $(TOOLS_BIN_DIR)/$(ENVSUBST_BIN)-$(ENVSUBST_VER))
 ENVSUBST_PKG := github.com/drone/envsubst/v2/cmd/envsubst
 
@@ -148,8 +152,8 @@ YQ_BIN := yq
 YQ :=  $(abspath $(TOOLS_BIN_DIR)/$(YQ_BIN)-$(YQ_VER))
 YQ_PKG := github.com/mikefarah/yq/v4
 
-GINGKO_VER := v2.4.0
 GINKGO_BIN := ginkgo
+GINGKO_VER := $(call get_go_version,github.com/onsi/ginkgo/v2)
 GINKGO := $(abspath $(TOOLS_BIN_DIR)/$(GINKGO_BIN)-$(GINGKO_VER))
 GINKGO_PKG := github.com/onsi/ginkgo/v2/ginkgo