arrow-cpp: fix build with clang-19

remove unsupported char_traits in buffer_test.cc.

fixed upstream
https://github.com/apache/arrow/pull/44493/files#diff-4b62e1208918e95c9fc3cf45848dd295dda6961cfec92cb1be98d83bf890fbf5

pkgs/by-name/ar/arrow-cpp/package.nix

@@ -3,6 +3,7 @@
   lib,
   fetchurl,
   fetchFromGitHub,
+  fetchpatch,
   fixDarwinDylibNames,
   autoconf,
   aws-sdk-cpp,
@@ -93,6 +94,17 @@ stdenv.mkDerivation (finalAttrs: {
 
   sourceRoot = "${finalAttrs.src.name}/cpp";
 
+  patches = [
+    # fixes build with libcxx-19 (llvm-19) remove on update
+    (fetchpatch {
+      name = "libcxx-19-fixes.patch";
+      url = "https://github.com/apache/arrow/commit/29e8ea011045ba4318a552567a26b2bb0a7d3f05.patch";
+      relative = "cpp";
+      includes = [ "src/arrow/buffer_test.cc" ];
+      hash = "sha256-ZHkznOilypi1J22d56PhLlw/hbz8RqwsOGDMqI1NsMs=";
+    })
+  ];
+
   # versions are all taken from
   # https://github.com/apache/arrow/blob/apache-arrow-${version}/cpp/thirdparty/versions.txt