phpactor: fix build

This fixes the generation of bash completion by patching the shebang of
the phpactor script before the generation is excuted.

pkgs/by-name/ph/phpactor/package.nix

@@ -19,6 +19,10 @@ php.buildComposerProject (finalAttrs: {
 
   nativeBuildInputs = [ installShellFiles ];
 
+  postPatch = ''
+    patchShebangs bin/phpactor
+  '';
+
   postInstall = ''
     installShellCompletion --cmd phpactor \
       --bash <($out/bin/phpactor completion bash)