Add additional Distinct() for safety

Author: javiercn

src/StaticWebAssetsSdk/Targets/Microsoft.NET.Sdk.StaticWebAssets.targets

@@ -676,7 +676,7 @@ Copyright (c) .NET Foundation. All rights reserved.
     </PropertyGroup>
 
     <DefineStaticWebAssets
-      CandidateAssets="@(Content)"
+      CandidateAssets="@(Content->Distinct())"
       FingerprintCandidates="$(StaticWebAssetsFingerprintContent)"
       FingerprintPatterns="@(StaticWebAssetFingerprintPattern)"
       RelativePathPattern="wwwroot/**"