[build] install .NET 10.x for BAR manifest (#10040)

The `Publish symbols and Push to Maestro` job and `generate and
publish BAR manifest` step fail with:

    Microsoft.NET.TargetFrameworkInference.targets(166,5): error NETSDK1045: The current .NET SDK does not support targeting .NET 10.0.  Either target .NET 9.0 or lower, or use a version of the .NET SDK that supports .NET 10.0. Download the .NET SDK from https://aka.ms/dotnet/download

It looks like we were using .NET 9 previews in the past:

    - task: UseDotNet@2
      displayName: Install .NET 9.x
      inputs:
        version: 9.x
        includePreviewVersions: true

So, we can use .NET 10 previews for this during .NET 10 development.

Author: jonathanpeppers

build-tools/automation/azure-pipelines.yaml

@@ -347,9 +347,9 @@ extends:
           submodules: recursive
 
         - task: UseDotNet@2
-          displayName: Install .NET 9.x
+          displayName: Install .NET 10.x
           inputs:
-            version: 9.x
+            version: 10.x
             includePreviewVersions: true
 
         # Download symbols to be published to the symbols artifact drop declared above