chore(spark): Remove logs of successful heartbeat (#2728)

### What changes were proposed in this pull request?

Remove logs of successful heartbeat

### Why are the changes needed?

simplify logs in spark driver side

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

Needn't

Author: zuston

client-spark/common/src/main/java/org/apache/uniffle/shuffle/manager/RssShuffleManagerBase.java

@@ -1528,7 +1528,6 @@ protected synchronized void startHeartbeat() {
             try {
               String appId = getAppId();
               shuffleWriteClient.sendAppHeartbeat(appId, heartbeatTimeout);
-              LOG.info("Finish send heartbeat to coordinator and servers");
             } catch (Exception e) {
               LOG.warn("Fail to send heartbeat to coordinator and servers", e);
             }