chore: remove warning when arn not parsed

The reason for removing the warning is, that not always a RoleArn may be present in the
ECS response, and hence having a warning in such scenario, every time credentials are retrieved, can
be annoying.

src/Credentials/EcsCredentialProvider.php

@@ -93,10 +93,6 @@ public function __invoke()
                                 $result['AccountId'] = $parsedArn->getAccountId();
                             } catch (\Exception $e) {
                                 // AccountId will be null
-                                trigger_error(
-                                    "An error occured while parsing the ARN string: " . $e->getMessage(),
-                                    E_USER_WARNING
-                                );
                             }
                         }