Fix future leak

src/main/java/me/cortex/voxy/client/core/rendering/GeometryCache.java

@@ -55,4 +55,11 @@ public class GeometryCache {
             sec.free();
         }
     }
+
+    public void free() {
+        this.lock.lock();
+        this.cache.values().forEach(BuiltSection::free);
+        this.cache.clear();
+        this.lock.unlock();
+    }
 }

src/main/java/me/cortex/voxy/client/core/rendering/hierachical/AsyncNodeManager.java

@@ -736,6 +736,7 @@ public class AsyncNodeManager {
 
         this.scatterWrite.free();
         this.multiMemcpy.free();
+        this.geometryCache.free();
     }
 
     public void addDebug(List<String> debug) {