linuxKernel.kernels.linux_testing_bcachefs: add pedrohlc to maintainers

pkgs/os-specific/linux/kernel/linux-testing-bcachefs.nix

···
 
     extraMeta = {
       branch = "master";
-      maintainers = with lib.maintainers; [ davidak Madouura ];
+      maintainers = with lib.maintainers; [ davidak Madouura pedrohlc ];
     };
   } // argsOverride;