Bump Polyfill from 7.17.0 to 7.18.0

Bumps [Polyfill](https://github.com/SimonCropp/Polyfill) from 7.17.0 to 7.18.0.
- [Commits](SimonCropp/Polyfill@7.17.0...7.18.0)

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

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

Author: dependabot[bot]

src/Directory.Packages.props

@@ -12,7 +12,7 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.12.0" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.13.0" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
-    <PackageVersion Include="Polyfill" Version="7.17.0" />
+    <PackageVersion Include="Polyfill" Version="7.18.0" />
     <PackageVersion Include="System.Formats.Asn1" Version="9.0.2" />
     <PackageVersion Include="Verify.SourceGenerators" Version="2.5.0" />
     <PackageVersion Include="Verify.Xunit" Version="28.12.1" />