Makefile: release v4.0.0

Makefile

@@ -43,7 +43,7 @@ FILES     := $$(find $$($(PACKAGE_DIRECTORIES)) -name "*.go")
 FAILPOINT_ENABLE  := $$(find $$PWD/ -type d | grep -vE "(\.git|tools)" | xargs tools/bin/failpoint-ctl enable)
 FAILPOINT_DISABLE := $$(find $$PWD/ -type d | grep -vE "(\.git|tools)" | xargs tools/bin/failpoint-ctl disable)
 
-LDFLAGS += -X "github.com/pingcap/parser/mysql.TiDBReleaseVersion=$(shell git describe --tags --dirty --always)"
+LDFLAGS += -X "github.com/pingcap/parser/mysql.TiDBReleaseVersion=v4.0.0"
 LDFLAGS += -X "github.com/pingcap/tidb/util/printer.TiDBBuildTS=$(shell date -u '+%Y-%m-%d %I:%M:%S')"
 LDFLAGS += -X "github.com/pingcap/tidb/util/printer.TiDBGitHash=$(shell git rev-parse HEAD)"
 LDFLAGS += -X "github.com/pingcap/tidb/util/printer.TiDBGitBranch=$(shell git rev-parse --abbrev-ref HEAD)"