Revert the Metal Experiment (#701)

Metal sounded like a good idea to get in the emulator but frankly I
underestimated just how experimental and not ready it was.
From my write up in the Discord:
```
As is, Metal supports only a few games.
The games it does support freeze on first use of not playing them via Vulkan, because shader translation is broken.
So you need to use a dirty hack to not delete all your shaders.
Not to mention it breaks many games via MoltenVK because of changes to the shared GPU code.

Merging Metal seemed like a great idea, because of the few games it does support.
But I don't think it's worth it. Many of the games it breaks via MoltenVK *don't work via Metal*. 
Which effectively makes current Ryubing worse for Mac users than Ryujinx 1.1.1403.

I think what I'm gonna do is revert Metal, and reopen it as a PR. That way, you can still take advantage of the Metal backend as is, but without making other games worse with no solution.
```

For what it's worth, the shader translation part could at least be
"fixed" by always applying a 30ms delay for shader translation to Metal.
That being said, that solution sucks ass.
The MoltenVK regressions are even worse.



I hope this is not a let down to the Mac users. I hope you realize I'm
reverting this because you're actively getting a worse experience with
it in the emulator.

src/Ryujinx.Graphics.Gpu/Shader/DiskCache/DiskCacheHostStorage.cs

@@ -324,11 +324,6 @@ namespace Ryujinx.Graphics.Gpu.Shader.DiskCache
 
                 bool loadHostCache = header.CodeGenVersion == CodeGenVersion;
 
-                if (context.Capabilities.Api == TargetApi.Metal)
-                {
-                    loadHostCache = false;
-                }
-
                 int programIndex = 0;
 
                 DataEntry entry = new();
@@ -397,8 +392,7 @@ namespace Ryujinx.Graphics.Gpu.Shader.DiskCache
                                 context,
                                 shaders,
                                 specState.PipelineState,
-                                specState.TransformFeedbackDescriptors != null,
-                                specState.ComputeState.GetLocalSize());
+                                specState.TransformFeedbackDescriptors != null);
 
                             IProgram hostProgram;
 
@@ -635,10 +629,7 @@ namespace Ryujinx.Graphics.Gpu.Shader.DiskCache
                 return;
             }
 
-            if (context.Capabilities.Api != TargetApi.Metal)
-            {
-                WriteHostCode(context, hostCode, program.Shaders, streams, timestamp);
-            }
+            WriteHostCode(context, hostCode, program.Shaders, streams, timestamp);
         }
 
         /// <summary>