Bump Polyfill from 7.8.0 to 7.9.0 in /src

Bumps [Polyfill](https://github.com/SimonCropp/Polyfill) from 7.8.0 to 7.9.0.
- [Commits](SimonCropp/Polyfill@7.8.0...7.9.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

src/Directory.Packages.props

@@ -9,7 +9,7 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.12.0" />
     <PackageVersion Include="Microsoft.CodeAnalysis.VisualBasic" Version="4.12.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
-    <PackageVersion Include="Polyfill" Version="7.8.0" />
+    <PackageVersion Include="Polyfill" Version="7.9.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.147" />
     <PackageVersion Include="Verify" Version="28.7.0" />
     <PackageVersion Include="Verify.DiffPlex" Version="3.1.2" />