lavapipe: bump memory allocation heap to 3GiB

this should still be a safe limit on all systems and archs

Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23077>

src/gallium/frontends/lavapipe/lvp_device.c

@@ -1218,7 +1218,7 @@ VKAPI_ATTR void VKAPI_CALL lvp_GetPhysicalDeviceMemoryProperties(
 
    pMemoryProperties->memoryHeapCount = 1;
    pMemoryProperties->memoryHeaps[0] = (VkMemoryHeap) {
-      .size = 2ULL*1024*1024*1024,
+      .size = 3ULL*1024*1024*1024,
       .flags = VK_MEMORY_HEAP_DEVICE_LOCAL_BIT,
    };
 }