add php-imagick

fixes #22

nix/image/php-ext.nix

@@ -35,6 +35,7 @@ in
         gmp
         apcu
         ffi
+        imagick
       ]
       ++ optionals (!debug) [
         smbclient # this breaks the build for no apparent reason

nix/image/php.nix

@@ -2,11 +2,7 @@
   lib,
   php,
   debug ? false,
-}: let
-  inherit (builtins) compareVersions;
-  inherit (lib) optionals;
-  withBlackfire = !debug && ((compareVersions php.version "8.1.0") == 1);
-in
+}:
 php.buildEnv {
   extensions = import ./php-ext.nix {inherit lib php debug;};
   extraConfig = ''