fix: Remove span dependency for ShellTask

Fixes errors such as :
```
System.IO.FileLoadException: Could not load file or assembly 'System.Numerics.Vectors, Version=4.1.3.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies.
```

src/Uno.Wasm.Bootstrap/ShellTask.cs

@@ -825,27 +825,30 @@ private void TryAdjustAOTProfile()
 
  if (profilePath != null)
  {
- var span = File.ReadAllBytes(profilePath).AsSpan();
+ var fileContent = File.ReadAllBytes(profilePath);
 
  var replacedMethods = new[] { "LoadIntoBufferAsync" };
 
  foreach (var method in replacedMethods)
  {
- var searchSpan = Encoding.ASCII.GetBytes(method).AsSpan();
+ var searchContent = Encoding.ASCII.GetBytes(method);
+ var slice = new byte[searchContent.Length];
 
- for (int i = 0; i < span.Length - searchSpan.Length; i++)
+ for (int i = 0; i < fileContent.Length - searchContent.Length; i++)
  {
- if (span[i] == searchSpan[0])
+ if (fileContent[i] == searchContent[0])
  {
- if (span.Slice(i, searchSpan.Length).SequenceEqual(searchSpan))
+ Buffer.BlockCopy(fileContent, i, slice, 0, searchContent.Length);
+
+ if (fileContent.SequenceEqual(searchContent))
  {
- span[i] = (byte)'_';
+ fileContent[i] = (byte)'_';
  }
  }
  }
  }
 
- File.WriteAllBytes(profilePath, span.ToArray());
+ File.WriteAllBytes(profilePath, fileContent);
  }
  }