Revert "python3Packages.pycapnp: backport patch for py314 compat"

This reverts commit 9518afa893.

Patch already included in 2.2.3 which causes applying the patch to fail

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

@@ -3,7 +3,6 @@
   buildPythonPackage,
   replaceVars,
   fetchFromGitHub,
-  fetchpatch,
   setuptools,
   wheel,
   capnproto,
@@ -36,12 +35,6 @@ buildPythonPackage rec {
     # other than the builtin schemas (based on quick GitHub code search), so I don't
     # think it's worthwhile.
     (replaceVars ./include-paths.patch { inherit capnproto; })
-
-    (fetchpatch {
-      url = "https://github.com/capnproto/pycapnp/commit/aa90ab6844df4718f02e2ca4974858d5ab0b079c.patch";
-      name = "python314-compat.patch";
-      hash = "sha256-pscOdgPotLZsW0XWyRTJigIDl3uWOizA1W0gQGZHSyg=";
-    })
   ];
 
   build-system = [