Remove unused code (#6991)

Author: loic-sharma

src/NuGetGallery.Core/NuGetGallery.Core.csproj

@@ -154,9 +154,7 @@
     <Compile Include="PackageMetadataExtensions.cs" />
     <Compile Include="PackageReaderCoreExtensions.cs" />
     <Compile Include="Packaging\InvalidPackageException.cs" />
-    <Compile Include="Packaging\ManifestEdit.cs" />
     <Compile Include="Packaging\ManifestValidator.cs" />
-    <Compile Include="Packaging\NupkgRewriter.cs" />
     <Compile Include="Packaging\PackageIdValidator.cs" />
     <Compile Include="Packaging\PackageMetadata.cs" />
     <Compile Include="Packaging\PackageMetadataStrings.cs" />

src/NuGetGallery.Core/Packaging/ManifestEdit.cs

@@ -96,7 +96,6 @@
     <Compile Include="Packaging\PackageIdValidatorTest.cs" />
     <Compile Include="Packaging\PackageMetadataFacts.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
-    <Compile Include="Packaging\NupkgRewriterFacts.cs" />
     <Compile Include="SemVerLevelKeyFacts.cs" />
     <Compile Include="Services\AccessConditionWrapperFacts.cs" />
     <Compile Include="Services\CoreLicenseFileServiceFacts.cs" />