Update dependencies from https://github.com/dotnet/core-setup build 20200909.3

Microsoft.NETCore.App
 From Version 3.1.0-preview3.19553.2 -> To Version 3.1.9-servicing.20459.3

Author: dotnet-maestro[bot]

eng/Version.Details.xml

@@ -30,9 +30,9 @@
       <Uri>https://github.com/dotnet/corefx</Uri>
       <Sha>046765913dff824f9ed0f2d2fe0fb9b111906cf5</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.NETCore.App" Version="3.1.0-preview3.19553.2">
+    <Dependency Name="Microsoft.NETCore.App" Version="3.1.9-servicing.20459.3">
       <Uri>https://github.com/dotnet/core-setup</Uri>
-      <Sha>13f35c3d86a40ff811bfde0b64cfb86431c19d15</Sha>
+      <Sha>1a04dd08e56bf52e88668c1ef2bd3f630ad442a5</Sha>
     </Dependency>
     <Dependency Name="optimization.IBC.CoreCLR" Version="99.99.99-master-20190912.1">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-optimization</Uri>

eng/Versions.props

@@ -27,7 +27,7 @@
     <MicrosoftBclAsyncInterfacesVersion>1.0.0-preview7.19326.2</MicrosoftBclAsyncInterfacesVersion>
     <SystemIOFileSystemAccessControlVersion>4.7.0-preview3.19551.4</SystemIOFileSystemAccessControlVersion>
     <!-- core-setup -->
-    <MicrosoftNETCoreAppVersion>3.1.0-preview3.19553.2</MicrosoftNETCoreAppVersion>
+    <MicrosoftNETCoreAppVersion>3.1.9-servicing.20459.3</MicrosoftNETCoreAppVersion>
     <!-- dotnet-core-internal-tooling -->
     <IbcMergePackageVersion>5.0.6-beta.19203.1</IbcMergePackageVersion>
     <!-- dotnet-optimization -->