chore: support $(GO_BIN) in make install / build

Makefile

@@ -3,6 +3,8 @@
 ################################################################################
 PROJECT_NAME := kava# unique namespace for project
 
+GO_BIN ?= go
+
 GIT_BRANCH := $(shell git rev-parse --abbrev-ref HEAD)
 GIT_COMMIT := $(shell git rev-parse HEAD)
 GIT_COMMIT_SHORT := $(shell git rev-parse --short HEAD)
@@ -175,16 +177,16 @@ all: install
 
 build: go.sum
 ifeq ($(OS), Windows_NT)
-	go build -mod=readonly $(BUILD_FLAGS) -o out/$(shell go env GOOS)/kava.exe ./cmd/kava
+	$(GO_BIN) build -mod=readonly $(BUILD_FLAGS) -o out/$(shell $(GO_BIN) env GOOS)/kava.exe ./cmd/kava
 else
-	go build -mod=readonly $(BUILD_FLAGS) -o out/$(shell go env GOOS)/kava ./cmd/kava
+	$(GO_BIN) build -mod=readonly $(BUILD_FLAGS) -o out/$(shell $(GO_BIN) env GOOS)/kava ./cmd/kava
 endif
 
 build-linux: go.sum
 	LEDGER_ENABLED=false GOOS=linux GOARCH=amd64 $(MAKE) build
 
 install: go.sum
-	go install -mod=readonly $(BUILD_FLAGS) ./cmd/kava
+	$(GO_BIN) install -mod=readonly $(BUILD_FLAGS) ./cmd/kava
 
 ########################################
 ### Tools & dependencies