Fixing tests (#189)

* Fixing Logs/Monolog.
* Fixing Aws\Xray.
* Fixing PropagatorTest.
* Fixing MongoDBInstrumentation import of CachedInstrumentation.
* Fixing Instrumentation/Laravel linting.
* Fixing Instrumentation/Symfony linting.
* Fixing Instrumentation/HttpAsyncClient linting.
* Fixing Instrumentation/Symfony linting.
* Fixing Symfony import.
* Updating Symfony composer deps.

src/HeadersPropagator.php

@@ -24,6 +24,7 @@ public static function instance(): self
     public function keys($carrier): array
     {
         assert($carrier instanceof Request);
+
         /** @psalm-suppress InvalidReturnStatement */
         return $carrier->headers->keys();
     }