Enable GO111MODULE=on globally in Makefile (#10939)

Now that our minimum required go version is 1.12 we can remove code that disables GO111MODULE globally and turn it on, so each command doesn't need it set specifically.

Also fixes a small bug with make pr that didn't work because GO111MODULE=on wasn't set

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

Makefile

@@ -1,7 +1,7 @@
 DIST := dist
 DIST_DIRS := $(DIST)/binaries $(DIST)/release
 IMPORT := code.gitea.io/gitea
-export GO111MODULE=off
+export GO111MODULE=on
 
 GO ?= go
 SED_INPLACE := sed -i
@@ -66,7 +66,7 @@ endif
 
 LDFLAGS := $(LDFLAGS) -X "main.MakeVersion=$(MAKE_VERSION)" -X "main.Version=$(GITEA_VERSION)" -X "main.Tags=$(TAGS)"
 
-GO_PACKAGES ?= $(filter-out code.gitea.io/gitea/integrations/migration-test,$(filter-out code.gitea.io/gitea/integrations,$(shell GO111MODULE=on $(GO) list -mod=vendor ./... | grep -v /vendor/)))
+GO_PACKAGES ?= $(filter-out code.gitea.io/gitea/integrations/migration-test,$(filter-out code.gitea.io/gitea/integrations,$(shell $(GO) list -mod=vendor ./... | grep -v /vendor/)))
 
 WEBPACK_SOURCES := $(shell find web_src/js web_src/less -type f)
 WEBPACK_CONFIGS := webpack.config.js
@@ -95,7 +95,7 @@ FOMANTIC_DEST := public/fomantic/semantic.min.js public/fomantic/semantic.min.cs
 FOMANTIC_DEST_DIR := public/fomantic
 
 #To update swagger use: GO111MODULE=on go get -u github.com/go-swagger/go-swagger/cmd/swagger@v0.20.1
-SWAGGER := GO111MODULE=on $(GO) run -mod=vendor github.com/go-swagger/go-swagger/cmd/swagger
+SWAGGER := $(GO) run -mod=vendor github.com/go-swagger/go-swagger/cmd/swagger
 SWAGGER_SPEC := templates/swagger/v1_json.tmpl
 SWAGGER_SPEC_S_TMPL := s|"basePath": *"/api/v1"|"basePath": "{{AppSubUrl}}/api/v1"|g
 SWAGGER_SPEC_S_JSON := s|"basePath": *"{{AppSubUrl}}/api/v1"|"basePath": "/api/v1"|g
@@ -273,7 +273,7 @@ lint-frontend: node_modules
 
 .PHONY: test
 test:
-	GO111MODULE=on $(GO) test $(GOTESTFLAGS) -mod=vendor -tags='sqlite sqlite_unlock_notify' $(GO_PACKAGES)
+	$(GO) test $(GOTESTFLAGS) -mod=vendor -tags='sqlite sqlite_unlock_notify' $(GO_PACKAGES)
 
 .PHONY: test-check
 test-check:
@@ -289,7 +289,7 @@ test-check:
 
 .PHONY: test\#%
 test\#%:
-	GO111MODULE=on $(GO) test -mod=vendor -tags='sqlite sqlite_unlock_notify' -run $* $(GO_PACKAGES)
+	$(GO) test -mod=vendor -tags='sqlite sqlite_unlock_notify' -run $* $(GO_PACKAGES)
 
 .PHONY: coverage
 coverage:
@@ -297,11 +297,11 @@ coverage:
 
 .PHONY: unit-test-coverage
 unit-test-coverage:
-	GO111MODULE=on $(GO) test $(GOTESTFLAGS) -mod=vendor -tags='sqlite sqlite_unlock_notify' -cover -coverprofile coverage.out $(GO_PACKAGES) && echo "\n==>\033[32m Ok\033[m\n" || exit 1
+	$(GO) test $(GOTESTFLAGS) -mod=vendor -tags='sqlite sqlite_unlock_notify' -cover -coverprofile coverage.out $(GO_PACKAGES) && echo "\n==>\033[32m Ok\033[m\n" || exit 1
 
 .PHONY: vendor
 vendor:
-	GO111MODULE=on $(GO) mod tidy && GO111MODULE=on $(GO) mod vendor
+	$(GO) mod tidy && $(GO) mod vendor
 
 .PHONY: test-vendor
 test-vendor: vendor
@@ -422,22 +422,22 @@ integration-test-coverage: integrations.cover.test generate-ini-mysql
 	GITEA_ROOT=${CURDIR} GITEA_CONF=integrations/mysql.ini ./integrations.cover.test -test.coverprofile=integration.coverage.out
 
 integrations.mysql.test: git-check $(GO_SOURCES)
-	GO111MODULE=on $(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -o integrations.mysql.test
+	$(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -o integrations.mysql.test
 
 integrations.mysql8.test: git-check $(GO_SOURCES)
-	GO111MODULE=on $(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -o integrations.mysql8.test
+	$(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -o integrations.mysql8.test
 
 integrations.pgsql.test: git-check $(GO_SOURCES)
-	GO111MODULE=on $(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -o integrations.pgsql.test
+	$(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -o integrations.pgsql.test
 
 integrations.mssql.test: git-check $(GO_SOURCES)
-	GO111MODULE=on $(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -o integrations.mssql.test
+	$(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -o integrations.mssql.test
 
 integrations.sqlite.test: git-check $(GO_SOURCES)
-	GO111MODULE=on $(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -o integrations.sqlite.test -tags 'sqlite sqlite_unlock_notify'
+	$(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -o integrations.sqlite.test -tags 'sqlite sqlite_unlock_notify'
 
 integrations.cover.test: git-check $(GO_SOURCES)
-	GO111MODULE=on $(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -coverpkg $(shell echo $(GO_PACKAGES) | tr ' ' ',') -o integrations.cover.test
+	$(GO) test $(GOTESTFLAGS) -mod=vendor -c code.gitea.io/gitea/integrations -coverpkg $(shell echo $(GO_PACKAGES) | tr ' ' ',') -o integrations.cover.test
 
 .PHONY: migrations.mysql.test
 migrations.mysql.test: $(GO_SOURCES)
@@ -477,10 +477,10 @@ backend: go-check generate $(EXECUTABLE)
 
 .PHONY: generate
 generate: $(TAGS_PREREQ)
-	GO111MODULE=on $(GO) generate -mod=vendor -tags '$(TAGS)' $(GO_PACKAGES)
+	$(GO) generate -mod=vendor -tags '$(TAGS)' $(GO_PACKAGES)
 
 $(EXECUTABLE): $(GO_SOURCES) $(TAGS_PREREQ)
-	GO111MODULE=on $(GO) build -mod=vendor $(GOFLAGS) $(EXTRA_GOFLAGS) -tags '$(TAGS)' -ldflags '-s -w $(LDFLAGS)' -o $@
+	$(GO) build -mod=vendor $(GOFLAGS) $(EXTRA_GOFLAGS) -tags '$(TAGS)' -ldflags '-s -w $(LDFLAGS)' -o $@
 
 .PHONY: release
 release: frontend generate release-windows release-linux release-darwin release-copy release-compress release-sources release-check
@@ -617,4 +617,4 @@ golangci-lint:
 		export BINARY="golangci-lint"; \
 		curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(GOPATH)/bin v1.24.0; \
 	fi
-	env GO111MODULE=on golangci-lint run --timeout 5m
+	golangci-lint run --timeout 5m