fix: reduce number of database queries caused by voter

src/Security/Voter/AssignmentVoter.php

@@ -74,13 +74,7 @@ class AssignmentVoter extends Voter
         // Only allow applications on empty slots
         $availableSlots = (int) $assignment->getAvailableDispositions();
         if (0 < $availableSlots) {
-            $dispositions = $this
-                ->entityManager
-                ->getRepository(Disposition::class)
-                ->findCurrentDispositionsByAssignment($assignment)
-            ;
-
-            return count($dispositions) < $availableSlots;
+            return $assignment->getDispositions()->count() < $availableSlots;
         }
 
         // Only teamers without existing applications may apply to the assignment
@@ -98,4 +92,4 @@ class AssignmentVoter extends Voter
 
         return false;
     }
-}
+}