fix: Remove support for .bc files

Replace with `.o`

src/Uno.Wasm.Bootstrap/ShellTask.cs

@@ -736,7 +736,7 @@ private void GenerateCSPMeta(StringBuilder extraBuilder)
 		private void GenerateBitcodeFiles()
 		{
 			var bitcodeFiles = Assets
-				?.Where(a => a.ItemSpec.EndsWith(".bc") || a.ItemSpec.EndsWith(".a"))
+				?.Where(a => a.ItemSpec.EndsWith(".o") || a.ItemSpec.EndsWith(".a"))
 				.Where(a => !bool.TryParse(a.GetMetadata("UnoAotCompile"), out var compile) || compile)
 				.Select(a => GetFilePaths(a).fullPath)
 				.ToArray()