Only update razor dependencies coming from maintenance-packages when source build is true (#11285)

Tracking issue: dotnet/sdk#45155

Unblocks: dotnet/sdk#45042

@ViktorHofer @ericstj @MichaelSimons @akoeplinger

Author: davidwengier

Directory.Packages.props

@@ -115,7 +115,7 @@
     <PackageVersion Include="System.Security.Cryptography.Xml" Version="7.0.1" />
     <PackageVersion Include="System.Text.Encodings.Web" Version="8.0.0" />
     <PackageVersion Include="System.Text.Json" Version="8.0.4" />
-    <PackageVersion Include="System.Threading.Tasks.Extensions" Version="4.5.4" />
+    <PackageVersion Include="System.Threading.Tasks.Extensions" Version="$(SystemThreadingTasksExtensionsVersion)" />
     <PackageVersion Include="xunit" Version="$(_XunitPackageVersion)" />
     <PackageVersion Include="Xunit.Combinatorial" Version="1.6.24" />
     <PackageVersion Include="xunit.extensibility.execution" Version="$(_XunitPackageVersion)" />
@@ -127,7 +127,7 @@
       at the appropriate version, in combination with using CentralPackageTransitivePinningEnabled, will
       ensure the correct version is used in all places
     -->
-    <PackageVersion Include="Microsoft.IO.Redist" Version="6.0.1" />
+    <PackageVersion Include="Microsoft.IO.Redist" Version="$(MicrosoftIORedistVersion)" />
     <PackageVersion Include="System.Formats.Asn1" Version="8.0.1" />
   </ItemGroup>
 </Project>

eng/Versions.props

@@ -100,4 +100,14 @@
     <XUnitVersion>2.6.6</XUnitVersion>
     <XUnitAnalyzersVersion>1.7.0</XUnitAnalyzersVersion>
   </PropertyGroup>
+
+  <!-- The maintenance-packages dependency versions need to be conditionally selected: https://github.com/dotnet/sdk/issues/45155 -->
+  <PropertyGroup Condition="'$(DotNetBuildSourceOnly)' != 'true'">
+    <MicrosoftIORedistVersion>6.0.1</MicrosoftIORedistVersion>
+    <SystemThreadingTasksExtensionsVersion>4.5.4</SystemThreadingTasksExtensionsVersion>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(DotNetBuildSourceOnly)' == 'true'">
+    <MicrosoftIORedistVersion>6.1.0</MicrosoftIORedistVersion>
+    <SystemThreadingTasksExtensionsVersion>4.6.0</SystemThreadingTasksExtensionsVersion>
+  </PropertyGroup>
 </Project>