[main] Update dependencies from dotnet/xharness (#24453)

This pull request updates the following dependencies

## From https://github.com/dotnet/xharness

- **Subscription**: [02e03784-16b3-4ced-b02a-3715797fc7da](https://maestro.dot.net/subscriptions?search=02e03784-16b3-4ced-b02a-3715797fc7da)
- **Build**: [20251215.1](https://dev.azure.com/dnceng/internal/_build/results?buildId=2861290) ([294675](https://maestro.dot.net/channel/2/github:dotnet:xharness/build/294675))
- **Date Produced**: December 15, 2025 11:38:54 AM UTC
- **Commit**: [39545dffac1cee604915785456394ef00a4a5456](dotnet/xharness@39545df)
- **Branch**: [main](https://github.com/dotnet/xharness/tree/main)

- **Dependency Updates**:
  - From [11.0.0-prerelease.25603.1 to 11.0.0-prerelease.25615.1][1]
     - Microsoft.DotNet.XHarness.iOS.Shared

[1]: dotnet/xharness@3df2923...39545df

Author: dotnet-maestro[bot]

eng/Version.Details.props

@@ -35,7 +35,7 @@ This file should be imported by eng/Versions.props
     <MicrosoftmacOSSdknet90_150PackageVersion>15.0.9617</MicrosoftmacOSSdknet90_150PackageVersion>
     <MicrosofttvOSSdknet90_180PackageVersion>18.0.9617</MicrosofttvOSSdknet90_180PackageVersion>
     <!-- dotnet/xharness dependencies -->
-    <MicrosoftDotNetXHarnessiOSSharedPackageVersion>11.0.0-prerelease.25603.1</MicrosoftDotNetXHarnessiOSSharedPackageVersion>
+    <MicrosoftDotNetXHarnessiOSSharedPackageVersion>11.0.0-prerelease.25615.1</MicrosoftDotNetXHarnessiOSSharedPackageVersion>
   </PropertyGroup>
   <!--Property group for alternate package version names-->
   <PropertyGroup>

eng/Version.Details.xml

@@ -107,9 +107,9 @@
       <Uri>https://github.com/dotnet/dotnet</Uri>
       <Sha>9441e5bb35fae9e956fdac4bd33ee537175e6d60</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.XHarness.iOS.Shared" Version="11.0.0-prerelease.25603.1">
+    <Dependency Name="Microsoft.DotNet.XHarness.iOS.Shared" Version="11.0.0-prerelease.25615.1">
       <Uri>https://github.com/dotnet/xharness</Uri>
-      <Sha>3df2923500447ee925d59f026c81720c7a9b4e4b</Sha>
+      <Sha>39545dffac1cee604915785456394ef00a4a5456</Sha>
     </Dependency>
     <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="10.0.0-beta.25612.111">
       <Uri>https://github.com/dotnet/dotnet</Uri>