[Ryujinx.Graphics.Texture] Address dotnet-format issues (#5375)

* dotnet format style --severity info

Some changes were manually reverted.

* Restore a few unused methods and variables

* Silence dotnet format IDE0060 warnings

* Silence dotnet format IDE0059 warnings

* Address or silence dotnet format CA2208 warnings

* Address most dotnet format whitespace warnings

* Apply dotnet format whitespace formatting

A few of them have been manually reverted and the corresponding warning was silenced

* Format if-blocks correctly

* Add comments to disabled warnings

* Simplify properties and array initialization, Use const when possible, Remove trailing commas

* Address IDE0251 warnings

* Silence IDE0060 in .editorconfig

* Revert "Simplify properties and array initialization, Use const when possible, Remove trailing commas"

This reverts commit 9462e4136c0a2100dc28b20cf9542e06790aa67e.

* dotnet format whitespace after rebase

* First dotnet format pass

* Apply suggestions from code review

Co-authored-by: Ac_K <Acoustik666@gmail.com>

* Address review feedback

* Update src/Ryujinx.Graphics.Texture/Astc/AstcDecoder.cs

Co-authored-by: Ac_K <Acoustik666@gmail.com>

---------

Co-authored-by: Ac_K <Acoustik666@gmail.com>

src/Ryujinx.Graphics.Texture/BCnEncoder.cs

@@ -28,8 +28,6 @@ namespace Ryujinx.Graphics.Texture
 
             for (int l = 0; l < levels; l++)
             {
-                int rgba8Size = width * height * depth * layers * 4;
-
                 int w = BitUtils.DivRoundUp(width, BlockWidth);
                 int h = BitUtils.DivRoundUp(height, BlockHeight);
 
@@ -38,8 +36,8 @@ namespace Ryujinx.Graphics.Texture
                     for (int z = 0; z < depth; z++)
                     {
                         BC7Encoder.Encode(
-                            output.AsMemory().Slice(imageBaseOOffs),
-                            data.AsMemory().Slice(imageBaseIOffs),
+                            output.AsMemory()[imageBaseOOffs..],
+                            data.AsMemory()[imageBaseIOffs..],
                             width,
                             height,
                             EncodeMode.Fast | EncodeMode.Multithreaded);
@@ -57,4 +55,4 @@ namespace Ryujinx.Graphics.Texture
             return output;
         }
     }
-}
+}