Bump Polyfill from 7.17.0 to 7.18.0 in /src

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] <support@github.com>

src/Directory.Packages.props

@@ -12,7 +12,7 @@
     <PackageVersion Include="NServiceBus" Version="9.2.6" />
     <PackageVersion Include="NUnit" Version="4.3.2" />
     <PackageVersion Include="NUnit3TestAdapter" Version="5.0.0" />
-    <PackageVersion Include="Polyfill" Version="7.17.0" />
+    <PackageVersion Include="Polyfill" Version="7.18.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.147" />
     <PackageVersion Include="System.ComponentModel.Annotations" Version="5.0.0" />
     <PackageVersion Include="Verify.NServiceBus" Version="10.3.4" />