MM-36411- Skip flaky TestUpdateConfigDiffInAuditRecord (#17927)

* MM-36411- Skip flaky TestUpdateConfigDiffInAuditRecord

The fix in https://github.com/mattermost/mattermost-server/pull/17777
doesn't seem to have worked fully as this was seen again.

Skipping it for now until we revisit this.

https://mattermost.atlassian.net/browse/MM-36411

```release-note
NONE
```

* Doing a file sync

```release-note
NONE
```

* Changed flush order

```release-note
NONE
```

api4/config_test.go

@@ -475,6 +475,8 @@ func TestUpdateConfigDiffInAuditRecord(t *testing.T) {
 	err = th.Server.Log.Flush(context.Background())
 	require.NoError(t, err)
 
+	require.NoError(t, logFile.Sync())
+
 	data, err := ioutil.ReadAll(logFile)
 	require.NoError(t, err)
 	require.NotEmpty(t, data)