Merge branch '5.4' into 6.0

* 5.4:
  [Process] intersect with getenv() in case-insensitive manner to get default envs
  [Serializer] fix support for lazy/unset properties
  Fix redundant type casts
  [Notifier] Fix AllMySms bridge body content
  Revert "[DoctrineBridge] add support for the JSON type"

Author: nicolas-grekas

Request.php

@@ -1841,7 +1841,7 @@ protected function preparePathInfo(): string
             return '/';
         }
 
-        return (string) $pathInfo;
+        return $pathInfo;
     }
 
     /**

Session/Flash/AutoExpireFlashBag.php

@@ -78,7 +78,7 @@ public function peek(string $type, array $default = []): array
      */
     public function peekAll(): array
     {
-        return \array_key_exists('display', $this->flashes) ? (array) $this->flashes['display'] : [];
+        return \array_key_exists('display', $this->flashes) ? $this->flashes['display'] : [];
     }
 
     /**

Session/Storage/Proxy/SessionHandlerProxy.php

@@ -21,7 +21,7 @@ class SessionHandlerProxy extends AbstractProxy implements \SessionHandlerInterf
     public function __construct(\SessionHandlerInterface $handler)
     {
         $this->handler = $handler;
-        $this->wrapper = ($handler instanceof \SessionHandler);
+        $this->wrapper = $handler instanceof \SessionHandler;
         $this->saveHandlerName = $this->wrapper ? ini_get('session.save_handler') : 'user';
     }
 
@@ -42,7 +42,7 @@ public function close(): bool
         return $this->handler->close();
     }
 
-    public function read(string $sessionId): string
+    public function read(string $sessionId): string|false
     {
         return $this->handler->read($sessionId);
     }