[improvement](statistics)Set enableQueryCache to false for statistics queries. (#45474)

### What problem does this PR solve?

Set enableQueryCache to false for statistics queries.

Issue Number: close #xxx

Related PR: #xxx

Problem Summary:

### Release note

None

Author: Jibing-Li

fe/fe-core/src/main/java/org/apache/doris/statistics/util/StatisticsUtil.java

@@ -223,6 +223,8 @@ public static AutoCloseConnectContext buildConnectContext(boolean useFileCacheFo
         sessionVariable.enablePushDownStringMinMax = true;
         sessionVariable.enableUniqueKeyPartialUpdate = false;
         sessionVariable.enableMaterializedViewRewrite = false;
+        sessionVariable.enableQueryCache = false;
+        sessionVariable.enableSqlCache = false;
         connectContext.setEnv(Env.getCurrentEnv());
         connectContext.setDatabase(FeConstants.INTERNAL_DB_NAME);
         connectContext.setQualifiedUser(UserIdentity.ADMIN.getQualifiedUser());