update description about vendoring in CONTRIBUTING.md (#18280)

* update description about vendoring in CONTRIBUTING.md

follow #18277

Signed-off-by: a101211279 <1012112796@qq.com>

* Update CONTRIBUTING.md

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

* fix and readd test-vendor step

* remove vendor from .gitattributes @silverwind

* simplify go mod check

Signed-off-by: a101211279 <1012112796@qq.com>

* Revert "remove vendor from .gitattributes @silverwind"

This reverts commit 4789e704cb.

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>

CONTRIBUTING.md

@@ -91,13 +91,12 @@ Here's how to run the test suite:
 
 ## Vendoring
 
-We keep a cached copy of dependencies within the `vendor/` directory,
-managing updates via [Modules](https://golang.org/cmd/go/#hdr-Module_maintenance).
+We manage dependencies via [Go Modules](https://golang.org/cmd/go/#hdr-Module_maintenance), more details: [go mod](https://go.dev/ref/mod).
 
-Pull requests should only include `vendor/` updates if they are part of
+Pull requests should only include `go.mod`, `go.sum` updates if they are part of
 the same change, be it a bugfix or a feature addition.
 
-The `vendor/` update needs to be justified as part of the PR description,
+The `go.mod`, `go.sum` update needs to be justified as part of the PR description,
 and must be verified by the reviewers and/or merger to always reference
 an existing upstream commit.
 

Makefile

@@ -295,7 +295,7 @@ checks: checks-frontend checks-backend
 checks-frontend: lockfile-check svg-check
 
 .PHONY: checks-backend
-checks-backend: swagger-check swagger-validate
+checks-backend: gomod-check swagger-check swagger-validate
 
 .PHONY: lint
 lint: lint-frontend lint-backend
@@ -369,11 +369,12 @@ unit-test-coverage:
 vendor:
 	$(GO) mod tidy && $(GO) mod vendor
 
-.PHONY: test-vendor
-test-vendor: vendor
-	@diff=$$(git diff vendor/); \
+.PHONY: gomod-check
+gomod-check:
+	@$(GO) mod tidy
+	@diff=$$(git diff go.sum); \
 	if [ -n "$$diff" ]; then \
-		echo "Please run 'make vendor' and commit the result:"; \
+		echo "Please run '$(GO) mod tidy' and commit the result:"; \
 		echo "$${diff}"; \
 		exit 1; \
 	fi