[Wasm] Ensure traling slash in OutputPath (#103768)

* [Wasm] Ensure traling slash in OutputPath

* Update src/mono/nuget/Microsoft.NET.Sdk.WebAssembly.Pack/build/Microsoft.NET.Sdk.WebAssembly.Browser.targets

Co-authored-by: Adeel Mujahid <3840695+am11@users.noreply.github.com>

---------

Co-authored-by: Adeel Mujahid <3840695+am11@users.noreply.github.com>

src/mono/nuget/Microsoft.NET.Sdk.WebAssembly.Pack/build/Microsoft.NET.Sdk.WebAssembly.Browser.targets

@@ -252,6 +252,7 @@ Copyright (c) .NET Foundation. All rights reserved.
     <PropertyGroup>
       <_WasmBuildWebCilPath>$([MSBuild]::NormalizeDirectory($(IntermediateOutputPath), 'webcil'))</_WasmBuildWebCilPath>
       <_WasmBuildTmpWebCilPath>$([MSBuild]::NormalizeDirectory($(IntermediateOutputPath), 'tmp-webcil'))</_WasmBuildTmpWebCilPath>
+      <_WasmBuildOuputPath>$([MSBuild]::NormalizeDirectory('$(OutputPath)', 'wwwroot'))</_WasmBuildOuputPath>
     </PropertyGroup>
 
     <ConvertDllsToWebCil Candidates="@(_BuildAssetsCandidates)" IntermediateOutputPath="$(_WasmBuildTmpWebCilPath)" OutputPath="$(_WasmBuildWebCilPath)" IsEnabled="$(_WasmEnableWebcil)">
@@ -267,7 +268,7 @@ Copyright (c) .NET Foundation. All rights reserved.
       AssetRole="Primary"
       CopyToOutputDirectory="PreserveNewest"
       CopyToPublishDirectory="Never"
-      ContentRoot="$(OutputPath)wwwroot"
+      ContentRoot="$(_WasmBuildOuputPath)"
       BasePath="$(StaticWebAssetBasePath)"
     >
       <Output TaskParameter="Assets" ItemName="WasmStaticWebAsset" />