Create judging_run_output together with judging_run rows

This means that the data state is more consistent.

Also, before the fix bb5d4c8, the judgedaemon
would retry the API call leading here after a 500 response
and then try to recreate the judging_run_output row of the
associated judging_run, which was already created in the first
API call, leading to an error
```
[Nov 23 14:47:57.923] judgedaemon[813572]: warning: Error while executing curl POST to url http://localhost/domjudge/api/judgehosts/add-judging-run/tiger-1/2589899: http status code: 500, request size = 5400, response: array (
  'code' => 500,
  'message' => 'An exception occurred while executing a query: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry \'2575471\' for key \'PRIMARY\'',
```

webapp/src/Controller/API/JudgehostController.php

@@ -948,13 +948,13 @@ private function addSingleJudgingRun(
                 throw new BadRequestHttpException(
                     'Inconsistent data, no judging run known with judgetaskid = ' . $judgeTaskId . '.');
             }
-            $judgingRunOutput = new JudgingRunOutput();
-            $judgingRun->setOutput($judgingRunOutput);
             $judgingRun
                 ->setRunresult($runResult)
                 ->setRuntime((float)$runTime)
                 ->setEndtime(Utils::now())
                 ->setTestcasedir($testcasedir);
+
+            $judgingRunOutput = $judgingRun->getOutput();
             $judgingRunOutput
                 ->setOutputRun(base64_decode($outputRun))
                 ->setOutputDiff(base64_decode($outputDiff))

webapp/src/Service/DOMJudgeService.php

@@ -1649,13 +1649,19 @@ private function actuallyCreateJudgetasks(int $priority, Judging $judging, int $
 
         $this->em->getConnection()->executeQuery($judgetaskInsertQuery, $judgetaskInsertParamsWithoutColon);
 
-        // Step 3: Insert the corresponding judging runs.
+        // Step 3: Insert the corresponding judging runs and output.
         $this->em->getConnection()->executeQuery(
             'INSERT INTO judging_run (judgingid, judgetaskid, testcaseid)
                     SELECT :judgingid, judgetaskid, testcase_id FROM judgetask
                     WHERE jobid = :judgingid ORDER BY judgetaskid',
             ['judgingid' => $judging->getJudgingid()]
         );
+
+        $this->em->getConnection()->executeQuery(
+            'INSERT INTO judging_run_output (runid)
+                    SELECT runid FROM judging_run WHERE judgingid = :judgingid',
+            ['judgingid' => $judging->getJudgingid()]
+        );
     }
 
     public function shadowMode(): bool