Resolve some inspections

osu.Framework/Graphics/OpenGL/Textures/TextureGL.cs

···
         /// <param name="upload">The <see cref="ITextureUpload"/> containing the data.</param>
         /// <param name="wrapModeS">The texture wrap mode in horizontal direction.</param>
         /// <param name="wrapModeT">The texture wrap mode in vertical direction.</param>
+        /// <param name="uploadOpacity">Whether the upload is opaque, transparent, or a mix of both..</param>
         internal abstract void SetData(ITextureUpload upload, WrapMode wrapModeS, WrapMode wrapModeT, Opacity? uploadOpacity);
 
         protected static Opacity ComputeOpacity(ITextureUpload upload)
···
         protected void UpdateOpacity(ITextureUpload upload, ref Opacity? uploadOpacity)
         {
             // Compute opacity if it doesn't have a value yet
-            uploadOpacity = uploadOpacity ?? ComputeOpacity(upload);
+            uploadOpacity ??= ComputeOpacity(upload);
 
             // Update the texture's opacity depending on the upload's opacity.
             // If the upload covers the entire bounds of the texture, it fully

osu.Framework/Graphics/Shapes/Box.cs

···
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using osu.Framework.Graphics.OpenGL;
-using osu.Framework.Graphics.OpenGL.Vertices;
-using osu.Framework.Graphics.Primitives;
 using osu.Framework.Graphics.Sprites;
 using osu.Framework.Graphics.Textures;
-using osu.Framework.Layout;
-using osuTK;
 
 namespace osu.Framework.Graphics.Shapes
 {

osu.Framework/Graphics/Sprites/SpriteDrawNode.cs

···
 
         protected override bool RequiresRoundedShader => base.RequiresRoundedShader || InflationAmount != Vector2.Zero;
 
-
         protected override void DrawOpaqueInterior(Action<TexturedVertex2D> vertexAction)
         {
             base.DrawOpaqueInterior(vertexAction);