mindustry: pin to Gradle 8

pkgs/by-name/mi/mindustry/package.nix

@@ -6,7 +6,7 @@
   makeDesktopItem,
   copyDesktopItems,
   fetchFromGitHub,
-  gradle,
+  gradle_8,
   jdk17,
   zenity,
 
@@ -43,6 +43,8 @@ let
   buildVersion = makeBuildVersion version;
 
   jdk = jdk17;
+  # "Deprecated Gradle features were used in this build, making it incompatible with Gradle 9.0."
+  gradle = gradle_8;
 
   Mindustry = fetchFromGitHub {
     owner = "Anuken";