Exclude archive diff target on pgo leg (#18918)

Author: jtschuster

src/SourceBuild/content/build.proj

@@ -26,8 +26,7 @@
   </Target>
 
   <Import Project="$(RepositoryEngineeringDir)build.sourcebuild.targets" Condition="'$(DotNetBuildSourceOnly)' == 'true'" />
-  <!-- ShortStack doesn't produce an SDK, and GetClosestOfficialSdk doesn't support finding non-portable SDKs -->
-  <Import Project="$(RepositoryEngineeringDir)sdkArchiveDiff.targets" Condition="'$(ShortStack)' != 'true' and '$(PortableBuild)' == 'true'" />
+  <Import Project="$(RepositoryEngineeringDir)sdkArchiveDiff.targets" Condition="'$(ShortStack)' != 'true' and '$(PortableBuild)' == 'true' and '$(PgoInstrument)' != 'true'" />
 
   <!-- Intentionally below the import to appear at the end. -->
   <Target Name="LogBuildOutputFolders"