[9.x] Updated to use str_starts_with (#40349)

* Updated to use str_starts_with().

* Style updates.

Author: ash-jc-allen

src/Illuminate/Routing/Route.php

@@ -914,7 +914,7 @@ protected function addGroupNamespaceToStringUses($action)
     {
         $groupStack = last($this->router->getGroupStack());
 
-        if (isset($groupStack['namespace']) && strpos($action, '\\') !== 0) {
+        if (isset($groupStack['namespace']) && ! str_starts_with($action, '\\')) {
             return $groupStack['namespace'].'\\'.$action;
         }
 

src/Illuminate/Routing/RouteGroup.php

@@ -41,7 +41,7 @@ public static function merge($new, $old, $prependExistingPrefix = true)
     protected static function formatNamespace($new, $old)
     {
         if (isset($new['namespace'])) {
-            return isset($old['namespace']) && strpos($new['namespace'], '\\') !== 0
+            return isset($old['namespace']) && ! str_starts_with($new['namespace'], '\\')
                     ? trim($old['namespace'], '\\').'\\'.trim($new['namespace'], '\\')
                     : trim($new['namespace'], '\\');
         }

src/Illuminate/Routing/Router.php

@@ -540,7 +540,7 @@ protected function prependGroupNamespace($class)
     {
         $group = end($this->groupStack);
 
-        return isset($group['namespace']) && strpos($class, '\\') !== 0
+        return isset($group['namespace']) && ! str_starts_with($class, '\\')
                 ? $group['namespace'].'\\'.$class : $class;
     }
 

src/Illuminate/Routing/UrlGenerator.php

@@ -507,7 +507,7 @@ protected function formatAction($action)
             $action = '\\'.implode('@', $action);
         }
 
-        if ($this->rootNamespace && strpos($action, '\\') !== 0) {
+        if ($this->rootNamespace && ! str_starts_with($action, '\\')) {
             return $this->rootNamespace.'\\'.$action;
         } else {
             return trim($action, '\\');