Disable Razor Source generators from VS Design time builds (#16702)

Follow up to #16648. We
want to continue allowing source generators from being used
in design time builds outside of Visual Studio. This is required
for hot reload of Razor files (.razor and .cshtml files) to continue working.

Author: pranavkm

src/RazorSdk/Targets/Microsoft.NET.Sdk.Razor.SourceGenerators.targets

@@ -9,10 +9,7 @@ Copyright (c) .NET Foundation. All rights reserved.
 -->
 
 <Project ToolsVersion="14.0">
-  <!-- Temporary workaround for design-time and build-time files being produced at
-        the same time. See https://github.com/dotnet/sdk/pull/16648 for more info. -->
   <Target Name="_PrepareRazorSourceGenerators"
-    Condition="'$(DesignTimeBuild)'!='true'"
     BeforeTargets="GenerateMSBuildEditorConfigFileShouldRun"
     DependsOnTargets="PrepareForRazorGenerate;PrepareForRazorComponentGenerate">
 
@@ -28,7 +25,11 @@ Copyright (c) .NET Foundation. All rights reserved.
       <_RazorAnalyzer Include="$(_RazorSdkToolsDirectoryRoot)Microsoft.CodeAnalysis.Razor.dll" />
       <_RazorAnalyzer Include="$(_RazorSdkSourceGeneratorDirectoryRoot)Microsoft.NET.Sdk.Razor.SourceGenerators.dll" />
 
-      <Analyzer Include="@(_RazorAnalyzer)" />
+      <!--
+        Temporary workaround for design-time and build-time files being produced at
+        the same time. See https://github.com/dotnet/sdk/pull/16648 for more info.
+      -->
+      <Analyzer Include="@(_RazorAnalyzer)" Condition="'$(BuildingInsideVisualStudio)' != 'true' OR '$(DesignTimeBuild)' != 'true'" />
 
       <RazorComponentWithTargetPath
         GeneratedOutputFullPath="$([System.IO.Path]::GetFullPath(%(GeneratedOutput)))"