Fix Iris shader animation time on 1.21

src/main/java/com/replaymod/render/hooks/EntityRendererHandler.java

@@ -41,6 +41,8 @@ public class EntityRendererHandler extends EventRegistrations implements WorldRe
 
     private final long startTime;
 
+    private long fakeFinishTimeNano;
+
     public EntityRendererHandler(RenderSettings settings, RenderInfo renderInfo) {
         this.settings = settings;
         this.renderInfo = renderInfo;
@@ -71,6 +73,7 @@ public class EntityRendererHandler extends EventRegistrations implements WorldRe
     }
 
     public void renderWorld(float partialTicks, long finishTimeNano) {
+        fakeFinishTimeNano = finishTimeNano;
         //#if MC>=11400
         PreRenderCallback.EVENT.invoker().preRender();
         //#else
@@ -142,6 +145,10 @@ public class EntityRendererHandler extends EventRegistrations implements WorldRe
         return this.renderInfo;
     }
 
+    public long getFakeFinishTimeNano() {
+        return fakeFinishTimeNano;
+    }
+
     public interface IEntityRenderer {
         void replayModRender_setHandler(EntityRendererHandler handler);
         EntityRendererHandler replayModRender_getHandler();

src/main/java/com/replaymod/render/mixin/Mixin_FakeSystemTimeUniforms_Iris.java

@@ -0,0 +1 @@
+// 1.21+