[main] Update dependencies from dotnet/arcade (#19691)

* Update dependencies from https://github.com/dotnet/arcade build 20260505.9
On relative base path root
Microsoft.DotNet.Arcade.Sdk From Version 10.0.0-beta.26222.2 -> To Version 10.0.0-beta.26255.9

* Fix flaky AsyncMemoize test: wait for all terminal events before asserting

The 'Cancel running jobs with the same key' test was racy - it waited
only for the Finished event before asserting Canceled count == 10, but
Canceled events from background jobs could still be in-flight. Now waits
for all 11 terminal events (10 Canceled + 1 Finished) before asserting.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: dotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com>
Co-authored-by: Tomas Grosup <tomasgrosup@microsoft.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 3 people

eng/Version.Details.props

@@ -6,7 +6,7 @@ This file should be imported by eng/Versions.props
 <Project>
   <PropertyGroup>
     <!-- dotnet-arcade dependencies -->
-    <MicrosoftDotNetArcadeSdkPackageVersion>10.0.0-beta.26222.2</MicrosoftDotNetArcadeSdkPackageVersion>
+    <MicrosoftDotNetArcadeSdkPackageVersion>10.0.0-beta.26255.9</MicrosoftDotNetArcadeSdkPackageVersion>
     <!-- dotnet-msbuild dependencies -->
     <MicrosoftBuildPackageVersion>18.6.4</MicrosoftBuildPackageVersion>
     <MicrosoftBuildFrameworkPackageVersion>18.6.4</MicrosoftBuildFrameworkPackageVersion>

eng/Version.Details.xml

@@ -76,9 +76,9 @@
     </Dependency>
   </ProductDependencies>
   <ToolsetDependencies>
-    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="10.0.0-beta.26222.2">
+    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="10.0.0-beta.26255.9">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>58713cb9a664ed67642127fcaf70b8c0c3b55ef2</Sha>
+      <Sha>658b93f2d1c0cdcdfb9c70113ff3c292cde97adb</Sha>
     </Dependency>
     <Dependency Name="optimization.windows_nt-x64.MIBC.Runtime" Version="1.0.0-prerelease.26180.1">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-optimization</Uri>

global.json

@@ -22,7 +22,7 @@
     "xcopy-msbuild": "18.0.0"
   },
   "msbuild-sdks": {
-    "Microsoft.DotNet.Arcade.Sdk": "10.0.0-beta.26222.2",
+    "Microsoft.DotNet.Arcade.Sdk": "10.0.0-beta.26255.9",
     "Microsoft.DotNet.Helix.Sdk": "8.0.0-beta.23255.2"
   }
 }

tests/FSharp.Compiler.ComponentTests/CompilerService/AsyncMemoize.fs

@@ -439,7 +439,10 @@ let ``Cancel running jobs with the same key`` () =
 
     job.Wait()
 
-    let events = eventsWhen events (received Finished)
+    // Wait for all 11 jobs to reach a terminal state (canceled/finished/failed)
+    // before asserting, to avoid snapshot races where some Canceled events
+    // haven't been observed yet when the Finished event arrives.
+    let events = eventsWhen events (fun e -> countOf Canceled e + countOf Finished e + countOf Failed e >= 11)
 
     Assert.Equal(0, events |> countOf Failed)