hash_extender: fix gcc-15 build

Without the change the build fails on `master` as
https://hydra.nixos.org/build/319912473:

```
In file included from hash_extender_engine.c:33:
tiger.h:1: error: header guard '__TIGER_H_' followed by '#define' of a different macro [-Werror=header-guard]
    1 | #ifndef __TIGER_H_
tiger.h:2: note: '__TIGER_H__' is defined here; did you mean '__TIGER_H_'?
    2 | #define __TIGER_H__
```

pkgs/by-name/ha/hash_extender/package.nix

@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  fetchpatch,
   openssl,
 }:
 
@@ -16,10 +17,27 @@ stdenv.mkDerivation {
     sha256 = "1fj118566hr1wv03az2w0iqknazsqqkak0mvlcvwpgr6midjqi9b";
   };
 
+  patches = [
+    # gcc-15 build fix:
+    #   https://github.com/iagox86/hash_extender/pull/15
+    (fetchpatch {
+      name = "gcc-15.patch";
+      url = "https://github.com/iagox86/hash_extender/commit/84d8d70eb10bcbe4dea2cf5a41d246d59a389e61.patch";
+      hash = "sha256-LCzv4FK+4WoJBYYUYB+zsC6358ZpTOxbE91W/1pFe6U=";
+    })
+  ];
+
   buildInputs = [ openssl ];
 
+  enableParallelBuilding = true;
   doCheck = true;
-  checkPhase = "./hash_extender --test";
+  checkPhase = ''
+    runHook preCheck
+
+    ./hash_extender --test
+
+    runHook postCheck
+  '';
 
   # https://github.com/iagox86/hash_extender/issues/26
   hardeningDisable = [ "fortify3" ];
@@ -27,8 +45,12 @@ stdenv.mkDerivation {
   env.NIX_CFLAGS_COMPILE = "-Wno-error=deprecated-declarations";
 
   installPhase = ''
+    runHook preInstall
+
     mkdir -p $out/bin
     cp hash_extender $out/bin
+
+    runHook postInstall
   '';
 
   meta = {