fix(linux-gpu): fix wrong return type

src/linux/hardware.zig

@@ -123,11 +123,11 @@ pub fn getGpuInfo(allocator: std.mem.Allocator) !std.ArrayList(GpuInfo) {
     }
 
     if (gpu_info_list.items.len == 0) {
-        return GpuInfo{
-            .gpu_name = undefined,
+        try gpu_info_list.append(GpuInfo{
+            .gpu_name = try allocator.dupe(u8, "Unknown"),
             .gpu_cores = 0,
             .gpu_freq = 0.0,
-        };
+        });
     }
 
     return gpu_info_list;