[fix](fe ut) Fix OlapQueryCacheTest failed (#27305)

1. 
```
java.lang.NullPointerException: null
        at org.apache.doris.catalog.Env.getCurrentSystemInfo(Env.java:793) ~[classes/:?]
        at org.apache.doris.qe.SimpleScheduler$UpdateBlacklistThread.run(SimpleScheduler.java:206) ~[classes/:?]
        at java.lang.Thread.run(Thread.java:750) ~[?:1.8.0_382]

java.lang.NullPointerException
        at org.apache.doris.qe.OlapQueryCacheTest.setUp(OlapQueryCacheTest.java:226)
```

2.
```
[ERROR] testSqlCacheKeyWithNestedViewForNereids  Time elapsed: 1.962 s  <<< FAILURE!
java.lang.AssertionError: SELECT command denied to user 'testCluster:testUser'@'192.168.1.1' for table 'internal: testCluster:testDb: appevent'
	at org.apache.doris.qe.OlapQueryCacheTest.parseSqlByNereids(OlapQueryCacheTest.java:579)
	at org.apache.doris.qe.OlapQueryCacheTest.testSqlCacheKeyWithNestedViewForNereids(OlapQueryCacheTest.java:1338)
```

3.
```
[ERROR] Tests run: 28, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 113.63 s <<< FAILURE! - in org.apache.doris.qe.OlapQueryCacheTest
[ERROR] testCacheModeTable  Time elapsed: 1.657 s  <<< ERROR!
java.lang.IllegalArgumentException: Value of type org.apache.doris.qe.QueryState incompatible with return type org.apache.doris.system.SystemInfoService of org.apache.doris.catalog.Env#getCurrentSystemInfo()
        at org.apache.doris.qe.OlapQueryCacheTest.setUp(OlapQueryCacheTest.java:156)
```

fe/fe-core/src/main/java/org/apache/doris/DorisFE.java

@@ -33,6 +33,7 @@
 import org.apache.doris.journal.bdbje.BDBToolOptions;
 import org.apache.doris.persist.meta.MetaReader;
 import org.apache.doris.qe.QeService;
+import org.apache.doris.qe.SimpleScheduler;
 import org.apache.doris.service.ExecuteEnv;
 import org.apache.doris.service.FeServer;
 import org.apache.doris.service.FrontendOptions;
@@ -194,6 +195,8 @@ public static void start(String dorisHomeDir, String pidDir, String[] args, Star
                 Env.getCurrentEnv().setHttpReady(true);
             }
 
+            SimpleScheduler.init();
+
             if (options.enableQeService) {
                 QeService qeService = new QeService(Config.query_port, Config.arrow_flight_sql_port,
                                                     ExecuteEnv.getInstance().getScheduler());

fe/fe-core/src/main/java/org/apache/doris/qe/SimpleScheduler.java

@@ -53,7 +53,7 @@ public class SimpleScheduler {
     private static Map<Long, Pair<Integer, String>> blacklistBackends = Maps.newConcurrentMap();
     private static UpdateBlacklistThread updateBlacklistThread;
 
-    static {
+    public static void init() {
         updateBlacklistThread = new UpdateBlacklistThread();
         updateBlacklistThread.start();
     }