gprof2dot: do not use pypy

- The package does not seem to function with `pypy` (#33997)
- Our default interpreter should be used. If one wants extra performance
(e.g. using PyPy) they can override or modify the expression however
they want, but not in Nixpkgs.

pkgs/top-level/all-packages.nix

@@ -2481,10 +2481,7 @@ with pkgs;
     callPackage ../tools/misc/graylog/plugins.nix { }
   );
 
-  gprof2dot = callPackage ../development/tools/profiling/gprof2dot {
-    # Using pypy provides significant performance improvements (~2x)
-    pythonPackages = pypyPackages;
-  };
+  gprof2dot = callPackage ../development/tools/profiling/gprof2dot { };
 
   graphviz = callPackage ../tools/graphics/graphviz {
     inherit (darwin.apple_sdk.frameworks) ApplicationServices;