use nullsafe operator in Connection (#41544)

Author: imanghafoori1

src/Illuminate/Database/Connection.php

@@ -852,9 +852,7 @@ public function beforeExecuting(Closure $callback)
      */
     public function listen(Closure $callback)
     {
-        if (isset($this->events)) {
-            $this->events->listen(Events\QueryExecuted::class, $callback);
-        }
+        $this->events?->listen(Events\QueryExecuted::class, $callback);
     }
 
     /**
@@ -865,11 +863,7 @@ public function listen(Closure $callback)
      */
     protected function fireConnectionEvent($event)
     {
-        if (! isset($this->events)) {
-            return;
-        }
-
-        return $this->events->dispatch(match ($event) {
+        return $this->events?->dispatch(match ($event) {
             'beganTransaction' => new TransactionBeginning($this),
             'committed' => new TransactionCommitted($this),
             'rollingBack' => new TransactionRolledBack($this),
@@ -885,9 +879,7 @@ protected function fireConnectionEvent($event)
      */
     protected function event($event)
     {
-        if (isset($this->events)) {
-            $this->events->dispatch($event);
-        }
+        $this->events?->dispatch($event);
     }
 
     /**

src/Illuminate/Redis/Connections/Connection.php

@@ -132,9 +132,7 @@ public function command($method, array $parameters = [])
      */
     protected function event($event)
     {
-        if (isset($this->events)) {
-            $this->events->dispatch($event);
-        }
+        $this->events?->dispatch($event);
     }
 
     /**
@@ -145,9 +143,7 @@ protected function event($event)
      */
     public function listen(Closure $callback)
     {
-        if (isset($this->events)) {
-            $this->events->listen(CommandExecuted::class, $callback);
-        }
+        $this->events?->listen(CommandExecuted::class, $callback);
     }
 
     /**