Bump Polyfill from 9.8.1 to 9.9.0

---
updated-dependencies:
- dependency-name: Polyfill
  dependency-version: 9.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

src/Directory.Packages.props

@@ -6,7 +6,7 @@
   <ItemGroup>
     <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
-    <PackageVersion Include="Polyfill" Version="9.8.1" />
+    <PackageVersion Include="Polyfill" Version="9.9.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.172" />
     <PackageVersion Include="Verify" Version="31.12.5" />
     <PackageVersion Include="Verify.DiffPlex" Version="3.1.2" />