Remove AutoDetectAndSetShaderMode method since it seems it does nothing

Except cause an exception because for some reason in one of the projects I get this:

```
System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
at System.Collections.Generic.List`1[T].get_Item (System.Int32 index) [0x00009] in :0
at ImmersiveVRTools.Editor.Common.WelcomeScreen.Utilities.AssetPathResolver.GetAssetFolderPathRelativeToScript (UnityEngine.ScriptableObject scriptableObject, System.Int32 folderDistanceFromFileRoot) [0x00022] in <9139b57e70db41b1b3e8ae7302e30088>:0
at FastScriptReload.Editor.FastScriptReloadPreference.SetCommonMaterialsShader (FastScriptReload.Editor.FastScriptReloadPreference+ShadersMode newShaderModeValue) [0x00001] in D:\git\borbeli\Assets\Plugins\Packages\handzlikchris.fastscriptreload\Source\Scripts\Editor\FastScriptReloadWelcomeScreen.cs:833
```

The reason I think it is not needed is that it calls FastScriptReloadPreference.SetCommonMaterialsShader which tries to set the shader on materials found in plugin's directory named Point but there are no materials in plugin's directory.

Start in FastScriptReloadWelcomeScreen.cs around line 833 and inspect AutoDetectAndSetShaderMode together with FastScriptReloadPreference.SetCommonMaterialsShader. Confirm how the Point material lookup causes the reported exception when no plugin materials exist. Done means the unnecessary call no longer triggers the exception and the related behavior is covered by the available project checks.

Scritto dal modello di indicizzazione a partire dal testo della issue.