Bump Microsoft.Build from 18.8.2 to 18.9.6 (#220)

Updated [Microsoft.Build](https://github.com/dotnet/msbuild) from 18.8.2
to 18.9.6.

<details>
<summary>Release notes</summary>

_Sourced from [Microsoft.Build's
releases](https://github.com/dotnet/msbuild/releases)._

## 18.9.6

## What's Changed
* [vs18.6] Update dependencies from dotnet/arcade by
@​dotnet-maestro[bot] in dotnet/msbuild#13793
* [vs18.0] Update dependencies from dotnet/arcade by
@​dotnet-maestro[bot] in dotnet/msbuild#13859
* [vs18.6] Update dependencies from dotnet/arcade by
@​dotnet-maestro[bot] in dotnet/msbuild#13858
* [vs18.7] Update dependencies from dotnet/arcade by
@​dotnet-maestro[bot] in dotnet/msbuild#13863
* CsWin32 follow-up: CLR metadata + TypeLib interop migration by
@​JeremyKuhne in dotnet/msbuild#13853
* Update vmr-sb-validation.yml for Azure Pipelines by @​meghnave in
dotnet/msbuild#13871
* Test: keep shell alive 15s in ToolTaskCanChangeCanonicalErrorFormat
(#​13734) by @​jankratochvilcz in
dotnet/msbuild#13878
* Add vs18.8 to merge-flow config by @​OvesN in
dotnet/msbuild#13877
* Stable branding for 18.8 release by @​OvesN in
dotnet/msbuild#13883
* Bump main to 18.9.0 after vs18.8 snap by @​OvesN in
dotnet/msbuild#13880
* Avoid checkout in insertion pipeline by @​rainersigwald in
dotnet/msbuild#13887
* Report actual launch path in MSB4216 for Runtime="NET" task host by
@​ViktorHofer in dotnet/msbuild#13889
* Migrate Tlblmp and AxImp to Multithreaded Execution by @​AlesProkop in
dotnet/msbuild#13708
* Replace ErrorUtilities assertion methods with Assumed API and BCL
throw helpers by @​DustinCampbell in
dotnet/msbuild#13790
* Fix CLR_E_SHIM_RUNTIMELOAD in RAR's IMetaDataDispenser activation by
@​JeremyKuhne in dotnet/msbuild#13899
* [main] Update dependencies from nuget/nuget.client by
@​dotnet-maestro[bot] in dotnet/msbuild#13905
* [main] Update dependencies from dotnet/arcade by @​dotnet-maestro[bot]
in dotnet/msbuild#13907
* [main] Update dependencies from dotnet/roslyn by @​dotnet-maestro[bot]
in dotnet/msbuild#13910
* [vs17.14] Update dependencies from dotnet/arcade by
@​dotnet-maestro[bot] in dotnet/msbuild#13908
* [vs18.0] Update dependencies from dotnet/arcade by
@​dotnet-maestro[bot] in dotnet/msbuild#13906
* Fix ToolTask output loss: increase EOF pipe timeout from 2s to 30s by
@​huulinhnguyen-dev in dotnet/msbuild#13767
* Improve symlink cycle condition by @​GangWang01 in
dotnet/msbuild#13901
* [vs18.6] Update dependencies from dotnet/arcade by
@​dotnet-maestro[bot] in dotnet/msbuild#13904
* Add flaky-test detection and auto-fix agentic workflows by
@​ViktorHofer in dotnet/msbuild#13915
* Quote --ignore-exit-code values so the quarantine pipeline does not
shell-split on Unix by @​ViktorHofer in
dotnet/msbuild#13918
* Fix flaky-test detector PR-evidence loss and raise scan limits by
@​ViktorHofer in dotnet/msbuild#13919
* Tighten the pr review agent by @​JanKrivanek in
dotnet/msbuild#13921
* Add environment variables for governance detection by @​ViktorHofer in
dotnet/msbuild#13920
* Change IsPackable to true and add IsShipping flag by @​ViktorHofer in
dotnet/msbuild#13924
* [vs18.7] Update dependencies from dotnet/arcade by
@​dotnet-maestro[bot] in dotnet/msbuild#13911
* Make flaky detector verify recurrence postdates the fix before
commenting by @​ViktorHofer in
dotnet/msbuild#13930
* Fix AbsolutePath.GetCanonicalForm process state leak on Windows by
@​OvesN in dotnet/msbuild#13788
* Fix flaky detector: unblock dnceng feed, fail fast, and defer
quarantine to a second run by @​ViktorHofer in
dotnet/msbuild#13936
* Update documentation for ImplicitUsings element by @​drewnoakes in
dotnet/msbuild#13900
* [vs18.6] Point OptProf bootstrapper at rel/stable instead of int.main
by @​AlesProkop in dotnet/msbuild#13923
* Add CS8618 suppressor for required MSBuild task properties by
@​AArnott in dotnet/msbuild#13926
* Tighten NodeLaunchData.EnvironmentOverrides nullability to
IDictionary<string, string?>? by @​OvesN with @​Copilot in
dotnet/msbuild#13815
* Fix ToolTask EOF wait to be STA-safe via CountdownEvent (MSB4018 in
AspNetCompiler) by @​YuliiaKovalova in
dotnet/msbuild#13917
* [automated] Merge branch 'vs18.6' => 'vs18.7' by @​github-actions[bot]
in dotnet/msbuild#13941
* Localized file check-in by OneLocBuild Task: Build definition ID 9434:
Build ID 14192258 by @​dotnet-bot in
dotnet/msbuild#13849
* Bumping to 10.0.8 runtime packages by @​OvesN in
dotnet/msbuild#13898
* Flaky-test workflow: reassure on empty PR list + drop local
reproduction (quarantine-first) by @​ViktorHofer in
dotnet/msbuild#13938
* [Flaky Test] Un-quarantine 5 consistently-green tests by
@​github-actions[bot] in dotnet/msbuild#13952
* Flaky-test detector: open PRs ready-for-review; drop
newly-filed-issues section from PR body by @​ViktorHofer in
dotnet/msbuild#13958
* [Flaky Test] Quarantine 4 flaky tests by @​github-actions[bot] in
dotnet/msbuild#13937
* Flaky-test: fix duplicate-issue bug by switching dedup key to a
visible code-block key by @​ViktorHofer in
dotnet/msbuild#13963
* CsWin32 follow-up: WindowsNative + VS Setup Configuration + remaining
hand-rolled interop by @​JeremyKuhne in
dotnet/msbuild#13872
* Add the reviewer release skill checking if the Learn article Change
waves is updated by @​GangWang01 in
dotnet/msbuild#13840
* [main] Source code updates from dotnet/dotnet by @​dotnet-maestro[bot]
in dotnet/msbuild#13977
 ... (truncated)

Commits viewable in [compare
view](dotnet/msbuild@v18.8.2...v18.9.6).
</details>

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Directory.Packages.props

@@ -4,7 +4,7 @@
     <CentralPackageTransitivePinningEnabled>false</CentralPackageTransitivePinningEnabled>
   </PropertyGroup>
   <ItemGroup>
-    <PackageVersion Include="Microsoft.Build" Version="18.8.2" />
+    <PackageVersion Include="Microsoft.Build" Version="18.9.6" />
     <PackageVersion Include="Microsoft.Build.Locator" Version="1.11.2" />
     <PackageVersion Include="Microsoft.CodeAnalysis.NetAnalyzers" Version="10.0.302" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.9.0" />