enhance: disallow tikv/rawkv usages (#30027)

Data write through rawkv API may pollute tikv data. It should be
disallowed.
We will add this check to all repos that involves metadata access.
In the longer term, we should have a metadata service that implements
access control.

relate: #30029

Signed-off-by: yiwangdr <yiwangdr@gmail.com>

.golangci.yml

@@ -106,6 +106,10 @@ linters-settings:
             desc: not allowed, use github.com/cockroachdb/errors
           - pkg: "io/ioutil"
             desc: ioutil is deprecated after 1.16, 1.17, use os and io package instead
+          - pkg: "github.com/tikv/client-go/rawkv"
+            desc: not allowed, use github.com/tikv/client-go/v2/txnkv
+          - pkg: "github.com/tikv/client-go/v2/rawkv"
+            desc: not allowed, use github.com/tikv/client-go/v2/txnkv
   forbidigo:
     forbid:
       - '^time\.Tick$'

internal/kv/tikv/main_test.go

@@ -17,11 +17,9 @@
 package tikv
 
 import (
-	"context"
 	"os"
 	"testing"
 
-	"github.com/tikv/client-go/v2/rawkv"
 	"github.com/tikv/client-go/v2/testutils"
 	tilib "github.com/tikv/client-go/v2/tikv"
 	"github.com/tikv/client-go/v2/txnkv"
@@ -29,15 +27,11 @@ import (
 	"github.com/milvus-io/milvus/pkg/util/paramtable"
 )
 
-var (
-	txnClient *txnkv.Client
-	rawClient *rawkv.Client
-)
+var txnClient *txnkv.Client
 
 // creates a local TiKV Store for testing purpose.
 func setupLocalTiKV() {
 	setupLocalTxn()
-	setupLocalRaw()
 }
 
 func setupLocalTxn() {
@@ -53,19 +47,6 @@ func setupLocalTxn() {
 	txnClient = &txnkv.Client{KVStore: store}
 }
 
-func setupLocalRaw() {
-	client, cluster, pdClient, err := testutils.NewMockTiKV("", nil)
-	if err != nil {
-		panic(err)
-	}
-	testutils.BootstrapWithSingleStore(cluster)
-	rawClient = &rawkv.Client{}
-	p := rawkv.ClientProbe{Client: rawClient}
-	p.SetPDClient(pdClient)
-	p.SetRegionCache(tilib.NewRegionCache(pdClient))
-	p.SetRPCClient(client)
-}
-
 // Connects to a remote TiKV service for testing purpose. By default, it assumes the TiKV is from localhost.
 func setupRemoteTiKV() {
 	pdsn := "127.0.0.1:2379"
@@ -74,10 +55,6 @@ func setupRemoteTiKV() {
 	if err != nil {
 		panic(err)
 	}
-	rawClient, err = rawkv.NewClientWithOpts(context.Background(), []string{pdsn})
-	if err != nil {
-		panic(err)
-	}
 }
 
 func setupTiKV(useRemote bool) {