Bump Polyfill from 2.4.0 to 2.6.5 in /src

Bumps [Polyfill](https://github.com/SimonCropp/Polyfill) from 2.4.0 to 2.6.5.
- [Commits](https://github.com/SimonCropp/Polyfill/commits)

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

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

src/NServiceBus.MicrosoftLogging/NServiceBus.MicrosoftLogging.csproj

@@ -4,7 +4,7 @@
     <TargetFrameworks>net48;net7.0</TargetFrameworks>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Polyfill" Version="2.4.0" PrivateAssets="all" />
+    <PackageReference Include="Polyfill" Version="2.6.5" PrivateAssets="all" />
     <PackageReference Include="NServiceBus" Version="8.1.6" />
     <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="8.0.0" />
     <PackageReference Include="ProjectDefaults" Version="1.0.109" PrivateAssets="all" />