JsonSerializer deserialize from bytes where possible

This is faster and uses way less memory
```
BenchmarkDotNet=v0.12.1, OS=fedora 32
Intel Core i7-6700HQ CPU 2.60GHz (Skylake), 1 CPU, 8 logical and 4 physical cores
.NET Core SDK=5.0.100
  [Host]     : .NET Core 5.0.0 (CoreCLR 5.0.20.51904, CoreFX 5.0.20.51904), X64 RyuJIT
  DefaultJob : .NET Core 5.0.0 (CoreCLR 5.0.20.51904, CoreFX 5.0.20.51904), X64 RyuJIT

| Method |     Mean |   Error |  StdDev |   Gen 0 | Gen 1 | Gen 2 | Allocated |
|------- |---------:|--------:|--------:|--------:|------:|------:|----------:|
|  Bytes | 158.4 us | 2.56 us | 2.14 us | 16.8457 |     - |     - |  52.08 KB |
| String | 172.8 us | 0.78 us | 0.70 us | 41.5039 |     - |     - | 127.82 KB |
| Custom | 155.5 us | 2.95 us | 2.76 us | 10.0098 |     - |     - |  31.27 KB |
```

1 files changed, 10 insertions, 10 deletions

diff --git a/Emby.Server.Implementations/ScheduledTasks/ScheduledTaskWorker.cs b/Emby.Server.Implementations/ScheduledTasks/ScheduledTaskWorker.cs
index 29440b64a..1d93b63a8 100644
--- a/Emby.Server.Implementations/ScheduledTasks/ScheduledTaskWorker.cs
+++ b/Emby.Server.Implementations/ScheduledTasks/ScheduledTaskWorker.cs
@@ -143,21 +143,21 @@ namespace Emby.Server.Implementations.ScheduledTasks
                     {
                         if (File.Exists(path))
                         {
-                            try
+                            var bytes = File.ReadAllBytes(path);
+                            if (bytes.Length > 0)
                             {
-                                var jsonString = File.ReadAllText(path, Encoding.UTF8);
-                                if (!string.IsNullOrWhiteSpace(jsonString))
+                                try
                                 {
-                                    _lastExecutionResult = JsonSerializer.Deserialize<TaskResult>(jsonString, _jsonOptions);
+                                    _lastExecutionResult = JsonSerializer.Deserialize<TaskResult>(bytes, _jsonOptions);
                                 }
-                                else
+                                catch (JsonException ex)
                                 {
-                                    _logger.LogDebug("Scheduled Task history file {Path} is empty. Skipping deserialization.", path);
+                                    _logger.LogError(ex, "Error deserializing {File}", path);
                                 }
                             }
-                            catch (Exception ex)
+                            else
                             {
-                                _logger.LogError(ex, "Error deserializing {File}", path);
+                                _logger.LogDebug("Scheduled Task history file {Path} is empty. Skipping deserialization.", path);
                             }
                         }
 
@@ -541,8 +541,8 @@ namespace Emby.Server.Implementations.ScheduledTasks
             TaskTriggerInfo[] list = null;
             if (File.Exists(path))
             {
-                var jsonString = File.ReadAllText(path, Encoding.UTF8);
-                list = JsonSerializer.Deserialize<TaskTriggerInfo[]>(jsonString, _jsonOptions);
+                var bytes = File.ReadAllBytes(path);
+                list = JsonSerializer.Deserialize<TaskTriggerInfo[]>(bytes, _jsonOptions);
             }
 
             // Return defaults if file doesn't exist.