fix: lint issues and DocumentDB test compatibility

- Fix ineffectual assignment lint error in extractCreateIndexesArgs
- Remove redundant nil check before len() (staticcheck S1009)
- Skip TestServerStatus on DocumentDB (serverStatus unsupported)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: h3n4l

admin_test.go

@@ -558,7 +558,8 @@ func TestCollectionStats(t *testing.T) {
 }
 
 func TestServerStatus(t *testing.T) {
-	testutil.RunOnAllDBs(t, func(t *testing.T, db testutil.TestDB) {
+	// serverStatus is not supported on DocumentDB
+	testutil.RunOnMongoDBOnly(t, func(t *testing.T, db testutil.TestDB) {
 		dbName := fmt.Sprintf("testdb_server_status_%s", db.Name)
 		defer testutil.CleanupDatabase(t, db.Client, dbName)
 

internal/translator/collection.go

@@ -2208,11 +2208,11 @@ func (v *visitor) extractCreateIndexesArgs(ctx mongodb.ICreateIndexesMethodConte
 		var keyDoc bson.D
 		for _, field := range doc {
 			if field.Key == "key" {
-				keyDoc, ok = field.Value.(bson.D)
+				keyDoc, _ = field.Value.(bson.D)
 				break
 			}
 		}
-		if keyDoc == nil || len(keyDoc) == 0 {
+		if len(keyDoc) == 0 {
 			v.err = fmt.Errorf("createIndexes() element %d must have a non-empty 'key' document", i)
 			return
 		}