Update dependencies from https://github.com/dotnet/corefx build 20190911.13 (#26680)

- Microsoft.NETCore.Platforms - 3.0.0-rc2.19461.13
- Microsoft.Private.CoreFx.NETCoreApp - 4.6.0-rc2.19461.13

Author: dotnet-maestro[bot]

eng/Version.Details.xml

@@ -18,13 +18,13 @@
       <Uri>https://github.com/dotnet/arcade</Uri>
       <Sha>8eb29ba860a3cfcfe68f9a8256caa7efc1f1aaba</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.Private.CoreFx.NETCoreApp" Version="4.6.0-rc2.19460.22">
+    <Dependency Name="Microsoft.Private.CoreFx.NETCoreApp" Version="4.6.0-rc2.19461.13">
       <Uri>https://github.com/dotnet/corefx</Uri>
-      <Sha>67fd971d57f9779c7acffc6d87934e311d968fa8</Sha>
+      <Sha>144ebb6ff997bf7a777206a233cdd8c03e13f60c</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.NETCore.Platforms" Version="3.0.0-rc2.19460.22">
+    <Dependency Name="Microsoft.NETCore.Platforms" Version="3.0.0-rc2.19461.13">
       <Uri>https://github.com/dotnet/corefx</Uri>
-      <Sha>67fd971d57f9779c7acffc6d87934e311d968fa8</Sha>
+      <Sha>144ebb6ff997bf7a777206a233cdd8c03e13f60c</Sha>
     </Dependency>
     <Dependency Name="Microsoft.NETCore.App" Version="3.0.0-rc2-19460-02">
       <Uri>https://github.com/dotnet/core-setup</Uri>

eng/Versions.props

@@ -21,8 +21,8 @@
     <!-- roslyn -->
     <MicrosoftNetCompilersToolsetVersion>3.3.0-beta2-19367-02</MicrosoftNetCompilersToolsetVersion>
     <!-- corefx -->
-    <MicrosoftPrivateCoreFxNETCoreAppVersion>4.6.0-rc2.19460.22</MicrosoftPrivateCoreFxNETCoreAppVersion>
-    <MicrosoftNETCorePlatformsVersion>3.0.0-rc2.19460.22</MicrosoftNETCorePlatformsVersion>
+    <MicrosoftPrivateCoreFxNETCoreAppVersion>4.6.0-rc2.19461.13</MicrosoftPrivateCoreFxNETCoreAppVersion>
+    <MicrosoftNETCorePlatformsVersion>3.0.0-rc2.19461.13</MicrosoftNETCorePlatformsVersion>
     <MicrosoftBclAsyncInterfacesVersion>1.0.0-preview7.19326.2</MicrosoftBclAsyncInterfacesVersion>
     <!-- core-setup -->
     <MicrosoftNETCoreAppVersion>3.0.0-rc2-19460-02</MicrosoftNETCoreAppVersion>