metal : fix recommendedMaxWorkingSetSize availability on legacy iOS/macOS (#19088)

Co-authored-by: chenbin11 <chenbin11@kuaishou.com>

ggml/src/ggml-metal/ggml-metal-device.m

@@ -785,8 +785,12 @@ ggml_metal_device_t ggml_metal_device_init(void) {
             dev->props.op_offload_min_batch_size  = getenv("GGML_OP_OFFLOAD_MIN_BATCH") ? atoi(getenv("GGML_OP_OFFLOAD_MIN_BATCH")) : 32;
 
             dev->props.max_buffer_size            = dev->mtl_device.maxBufferLength;
-            dev->props.max_working_set_size       = dev->mtl_device.recommendedMaxWorkingSetSize;
             dev->props.max_theadgroup_memory_size = dev->mtl_device.maxThreadgroupMemoryLength;
+            if (@available(macOS 10.12, iOS 16.0, *)) {
+                dev->props.max_working_set_size   = dev->mtl_device.recommendedMaxWorkingSetSize;
+            } else {
+                dev->props.max_working_set_size   = dev->mtl_device.maxBufferLength;
+            }
 
             strncpy(dev->props.name, [[dev->mtl_device name] UTF8String], sizeof(dev->props.name) - 1);