set GOPROXY only if it is not empty (#330)

* set GOPROXY only if it is not empty

* bump year 2025 for boilerplate.go.txt

Author: pacoxu

Makefile

@@ -177,7 +177,7 @@ run: manifests generate fmt vet ## Run a controller from your host.
 PLATFORMS ?= linux/arm64,linux/amd64,linux/s390x,linux/ppc64le
 .PHONY: docker-buildx
 docker-buildx: ## Build and push docker image for the manager for cross-platform support
-	export GOPROXY=$(GOPROXY)
+	[ -n "$(GOPROXY)" ] && export GOPROXY=$(GOPROXY)
 	# copy existing Dockerfile and insert --platform=${BUILDPLATFORM} into Dockerfile.cross, and preserve the original Dockerfile
 	sed -e '1 s/\(^FROM\)/FROM --platform=\$$\{BUILDPLATFORM\}/; t' -e ' 1,// s//FROM --platform=\$$\{BUILDPLATFORM\}/' Dockerfile > Dockerfile.cross
 	- $(CONTAINER_TOOL) buildx create --name project-v3-builder

hack/boilerplate.go.txt

@@ -1,5 +1,5 @@
 /*
-Copyright 2024 The InftyAI Team.
+Copyright 2025 The InftyAI Team.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -12,4 +12,4 @@ distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
-*/
+*/