python311Packages.caio: fix build on darwin

pkgs/development/python-modules/caio/default.nix

@@ -1,4 +1,5 @@
 { lib
+, stdenv
 , aiomisc
 , buildPythonPackage
 , fetchFromGitHub
@@ -27,6 +28,10 @@ buildPythonPackage rec {
     pytestCheckHook
   ];
 
+  env.NIX_CFLAGS_COMPILE = toString (lib.optionals stdenv.cc.isClang [
+    "-Wno-error=implicit-function-declaration"
+  ]);
+
   pythonImportsCheck = [
     "caio"
   ];