[enhance](job) optimize auto resume rule to adapt VCG failover (#59421)

### What problem does this PR solve?

In #52515 introduces VCG(Virtual
Compute Group) to be used for multi availability zone disaster recovery.

But routine load job do not adapt it perfectly: If a cluster in an
availability zone crashes, VCG provides disaster recovery capabilities,
but the job will not be automatically resume. So this PR removed the
`dead BE count` calculation when judge `isNeedAutoSchedule`.

### Release note

None

Author: sollhui

fe/fe-common/src/main/java/org/apache/doris/common/Config.java

@@ -1319,12 +1319,6 @@ public class Config extends ConfigBase {
     @ConfField
     public static boolean check_java_version = true;
 
-    /**
-     * it can't auto-resume routine load job as long as one of the backends is down
-     */
-    @ConfField(mutable = true, masterOnly = true)
-    public static int max_tolerable_backend_down_num = 0;
-
     /**
      * a period for auto resume routine load
      */

fe/fe-core/src/main/java/org/apache/doris/load/routineload/ScheduleRule.java

@@ -59,16 +59,6 @@ public static boolean isNeedAutoSchedule(RoutineLoadJob jobRoutine) {
                 && jobRoutine.pauseReason.getCode() != InternalErrorCode.MANUAL_PAUSE_ERR
                 && jobRoutine.pauseReason.getCode() != InternalErrorCode.TOO_MANY_FAILURE_ROWS_ERR
                 && jobRoutine.pauseReason.getCode() != InternalErrorCode.CANNOT_RESUME_ERR) {
-            int dead = deadBeCount();
-            if (dead > Config.max_tolerable_backend_down_num) {
-                if (LOG.isDebugEnabled()) {
-                    LOG.debug("dead backend num {} is larger than config {}, "
-                                    + "routine load job {} can not be auto rescheduled",
-                            dead, Config.max_tolerable_backend_down_num, jobRoutine.id);
-                }
-                return false;
-            }
-
             if (jobRoutine.latestResumeTimestamp == 0) { //the first resume
                 jobRoutine.latestResumeTimestamp = System.currentTimeMillis();
                 jobRoutine.autoResumeCount = 1;