[build] update to .NET 10 GA (#1323)

.NET version updates:

* Updated the `dotnetVersion` variable from `9.0.306` to `9.0.308` in `build/ci/variables.yml` to use the latest stable .NET 9 release.
* Updated the `dotnetNextVersion` variable from the preview release `10.0.100-rc.2.25502.107` to the stable release `10.0.100` in `build/ci/variables.yml`.

Author: jonathanpeppers

build/ci/setup-environment.yml

@@ -16,15 +16,13 @@ steps:
     displayName: 'Use dotnet $(dotnetVersion)'
     inputs:
       version: $(dotnetVersion)
-      includePreviewVersions: true
     condition: ne('$(dotnetVersion)', '')
 
   - task: UseDotNet@2
     displayName: 'Use dotnet $(dotnetNextVersion)'
     inputs:
       version: $(dotnetNextVersion)
       performMultiLevelLookup: true
-      includePreviewVersions: true
     condition: ne('$(dotnetNextVersion)', '')
 
   - script: dotnet --info

build/ci/variables.yml

@@ -19,7 +19,7 @@ variables:
   macosAgentPoolName: VSEng-VSMac-Xamarin-Shared                                        # macOS VM pool name
 
   # Tool variables
-  dotnetVersion: '9.0.306'                                                              # .NET version to install on agent
+  dotnetVersion: '9.0.308'                                                              # .NET version to install on agent
   dotnetFrameworkVersion: 9                                                             # The number to use for TF (eg: netX.0-android)
   dotnetNuGetOrgSource: 'https://api.nuget.org/v3/index.json'                           # NuGet.org URL to find workloads
 
@@ -34,7 +34,7 @@ variables:
   extendedTestAssembly: tests/extended/bin/$(configuration)/net$(dotnetFrameworkVersion).0/ExtendedTests.dll    # Extended tests compiled binary
 
   # dotnet-next test variables
-  dotnetNextVersion: 10.0.100-rc.2.25502.107                                            # .NET preview version to install
+  dotnetNextVersion: 10.0.100                                                           # .NET version to install
   dotnetNextFrameworkVersion: 10                                                        # The number to use for TF (eg: netX.0-android)
 
   # dnceng-public variables